diff --git a/src/auto/configure b/src/auto/configure
index ff3a63b..ba0d0b0 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -810,6 +810,7 @@
 enable_rubyinterp
 with_ruby_command
 enable_cscope
+enable_termtruecolor
 enable_workshop
 enable_netbeans
 enable_channel
@@ -1476,6 +1477,7 @@
   --enable-tclinterp=OPTS      Include Tcl interpreter. default=no OPTS=no/yes/dynamic
   --enable-rubyinterp=OPTS     Include Ruby interpreter.  default=no OPTS=no/yes/dynamic
   --enable-cscope         Include cscope interface.
+  --enable-termtruecolor      Include support for 24-bit colors in ISO-8613-3 compatible terminals
   --enable-workshop       Include Sun Visual Workshop support.
   --disable-netbeans      Disable NetBeans integration support.
   --disable-channel      Disable process communication support.
@@ -7216,6 +7218,22 @@
 
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking --enable-termtruecolor argument" >&5
+$as_echo_n "checking --enable-termtruecolor argument... " >&6; }
+# Check whether --enable-termtruecolor was given.
+if test "${enable_termtruecolor+set}" = set; then :
+  enableval=$enable_termtruecolor;
+else
+  enable_termtruecolor="no"
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $enable_termtruecolor" >&5
+$as_echo "$enable_termtruecolor" >&6; }
+if test "$enable_termtruecolor" = "yes"; then
+  $as_echo "#define FEAT_TERMTRUECOLOR 1" >>confdefs.h
+
+fi
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking --enable-workshop argument" >&5
 $as_echo_n "checking --enable-workshop argument... " >&6; }
 # Check whether --enable-workshop was given.
diff --git a/src/config.h.in b/src/config.h.in
index 9d35e48..6c0f779 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -362,6 +362,9 @@
 /* Define for linking via dlopen() or LoadLibrary() */
 #undef DYNAMIC_TCL
 
+/* Define if you want 24-bit colors in ISO-8613-3 compatible terminals. */
+#undef FEAT_TERMTRUECOLOR
+
 /* Define if you want to add support for ACL */
 #undef HAVE_POSIX_ACL
 #undef HAVE_SOLARIS_ZFS_ACL
diff --git a/src/configure.in b/src/configure.in
index 279ed47..d1d7838 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -1926,6 +1926,15 @@
   AC_DEFINE(FEAT_CSCOPE)
 fi
 
+AC_MSG_CHECKING(--enable-termtruecolor argument)
+AC_ARG_ENABLE(termtruecolor,
+	[  --enable-termtruecolor      Include support for 24-bit colors in ISO-8613-3 compatible terminals], ,
+	[enable_termtruecolor="no"])
+AC_MSG_RESULT($enable_termtruecolor)
+if test "$enable_termtruecolor" = "yes"; then
+  AC_DEFINE(FEAT_TERMTRUECOLOR)
+fi
+
 AC_MSG_CHECKING(--enable-workshop argument)
 AC_ARG_ENABLE(workshop,
 	[  --enable-workshop       Include Sun Visual Workshop support.], ,
diff --git a/src/eval.c b/src/eval.c
index b82a98f..3542b77 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -14044,6 +14044,9 @@
 #ifdef FEAT_TERMRESPONSE
 	"termresponse",
 #endif
+#ifdef FEAT_TERMTRUECOLOR
+	"termtruecolor",
+#endif
 #ifdef FEAT_TEXTOBJ
 	"textobjects",
 #endif
diff --git a/src/globals.h b/src/globals.h
index 5effdb5..8cc9bed 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -369,6 +369,10 @@
 EXTERN int	cterm_normal_fg_color INIT(= 0);
 EXTERN int	cterm_normal_fg_bold INIT(= 0);
 EXTERN int	cterm_normal_bg_color INIT(= 0);
+#ifdef FEAT_TERMTRUECOLOR
+EXTERN long_u	cterm_normal_fg_gui_color INIT(= INVALCOLOR);
+EXTERN long_u	cterm_normal_bg_gui_color INIT(= INVALCOLOR);
+#endif
 
 #ifdef FEAT_AUTOCMD
 EXTERN int	autocmd_busy INIT(= FALSE);	/* Is apply_autocmds() busy? */
diff --git a/src/hardcopy.c b/src/hardcopy.c
index f65a6dd..aaa2010 100644
--- a/src/hardcopy.c
+++ b/src/hardcopy.c
@@ -164,7 +164,7 @@
 
 #if (defined(FEAT_MBYTE) && defined(FEAT_POSTSCRIPT)) || defined(PROTO)
 /*
- * Parse 'printoptions' and set the flags in "printer_opts".
+ * Parse 'printmbfont' and set the flags in "mbfont_opts".
  * Returns an error message or NULL;
  */
     char_u *
@@ -307,8 +307,8 @@
     pattr->underline = (highlight_has_attr(hl_id, HL_UNDERLINE, modec) != NULL);
     pattr->undercurl = (highlight_has_attr(hl_id, HL_UNDERCURL, modec) != NULL);
 
-# ifdef FEAT_GUI
-    if (gui.in_use)
+# if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
+    if (USE_24BIT)
     {
 	bg_color = highlight_gui_color_rgb(hl_id, FALSE);
 	if (bg_color == PRCOLOR_BLACK)
diff --git a/src/option.c b/src/option.c
index a5b403c..da02864 100644
--- a/src/option.c
+++ b/src/option.c
@@ -1305,7 +1305,16 @@
 			    {(char_u *)NULL, (char_u *)0L}
 #endif
 			    SCRIPTID_INIT},
-    {"guicursor",    "gcr",  P_STRING|P_VI_DEF|P_ONECOMMA|P_NODUP,
+    {"guicolors",   "gcol", P_BOOL|P_VI_DEF|P_VIM|P_RCLR,
+#ifdef FEAT_TERMTRUECOLOR
+			    (char_u *)&p_guicolors, PV_NONE,
+			    {(char_u *)FALSE, (char_u *)FALSE}
+#else
+			    (char_u*)NULL, PV_NONE,
+			    {(char_u *)FALSE, (char_u *)FALSE}
+#endif
+			    SCRIPTID_INIT},
+    {"guicursor",    "gcr", P_STRING|P_VI_DEF|P_ONECOMMA|P_NODUP,
 #ifdef CURSOR_SHAPE
 			    (char_u *)&p_guicursor, PV_NONE,
 			    {
@@ -3011,6 +3020,8 @@
     p_term("t_xs", T_XS)
     p_term("t_ZH", T_CZH)
     p_term("t_ZR", T_CZR)
+    p_term("t_8f", T_8F)
+    p_term("t_8b", T_8B)
 
 /* terminal key codes are not in here */
 
@@ -8353,6 +8364,17 @@
 
 #endif
 
+#ifdef FEAT_TERMTRUECOLOR
+    /* 'guicolors' */
+    else if ((int *)varp == &p_guicolors)
+    {
+# ifdef FEAT_GUI
+	if (!gui.in_use && !gui.starting)
+# endif
+	    highlight_gui_started();
+    }
+#endif
+
     /*
      * End of handling side effects for bool options.
      */
diff --git a/src/option.h b/src/option.h
index cf7ba04..60889ab 100644
--- a/src/option.h
+++ b/src/option.h
@@ -527,6 +527,9 @@
 EXTERN char_u	*p_header;	/* 'printheader' */
 #endif
 EXTERN int	p_prompt;	/* 'prompt' */
+#ifdef FEAT_TERMTRUECOLOR
+EXTERN int	p_guicolors;	/* 'guicolors' */
+#endif
 #ifdef FEAT_GUI
 EXTERN char_u	*p_guifont;	/* 'guifont' */
 # ifdef FEAT_XFONTSET
diff --git a/src/proto/term.pro b/src/proto/term.pro
index 5836979..cd2ca26 100644
--- a/src/proto/term.pro
+++ b/src/proto/term.pro
@@ -1,4 +1,7 @@
 /* term.c */
+guicolor_T termtrue_mch_get_color(char_u *name);
+guicolor_T termtrue_get_color(char_u *name);
+long_u termtrue_mch_get_rgb(guicolor_T color);
 int set_termname(char_u *term);
 void set_mouse_termcode(int n, char_u *s);
 void del_mouse_termcode(int n);
@@ -22,6 +25,8 @@
 void term_set_winsize(int width, int height);
 void term_fg_color(int n);
 void term_bg_color(int n);
+void term_fg_rgb_color(long_u rgb);
+void term_bg_rgb_color(long_u rgb);
 void term_settitle(char_u *title);
 void ttest(int pairs);
 void add_long_to_buf(long_u val, char_u *dst);
diff --git a/src/screen.c b/src/screen.c
index b92cbf9..5dc8ffe 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -7828,7 +7828,7 @@
 	{
 	    if (attr > HL_ALL)				/* special HL attr. */
 	    {
-		if (t_colors > 1)
+		if (IS_CTERM)
 		    aep = syn_cterm_attr2entry(attr);
 		else
 		    aep = syn_term_attr2entry(attr);
@@ -7839,8 +7839,16 @@
 	    }
 	    if ((attr & HL_BOLD) && T_MD != NULL)	/* bold */
 		out_str(T_MD);
-	    else if (aep != NULL && t_colors > 1 && aep->ae_u.cterm.fg_color
-						      && cterm_normal_fg_bold)
+	    else if (aep != NULL && cterm_normal_fg_bold &&
+#ifdef FEAT_TERMTRUECOLOR
+			(p_guicolors ?
+			    (aep->ae_u.cterm.fg_rgb != INVALCOLOR):
+#endif
+			    (t_colors > 1 && aep->ae_u.cterm.fg_color)
+#ifdef FEAT_TERMTRUECOLOR
+			)
+#endif
+		    )
 		/* If the Normal FG color has BOLD attribute and the new HL
 		 * has a FG color defined, clear BOLD. */
 		out_str(T_ME);
@@ -7860,17 +7868,29 @@
 	     */
 	    if (aep != NULL)
 	    {
-		if (t_colors > 1)
+#ifdef FEAT_TERMTRUECOLOR
+		if (p_guicolors)
 		{
-		    if (aep->ae_u.cterm.fg_color)
-			term_fg_color(aep->ae_u.cterm.fg_color - 1);
-		    if (aep->ae_u.cterm.bg_color)
-			term_bg_color(aep->ae_u.cterm.bg_color - 1);
+		    if (aep->ae_u.cterm.fg_rgb != INVALCOLOR)
+			term_fg_rgb_color(aep->ae_u.cterm.fg_rgb);
+		    if (aep->ae_u.cterm.bg_rgb != INVALCOLOR)
+			term_bg_rgb_color(aep->ae_u.cterm.bg_rgb);
 		}
 		else
+#endif
 		{
-		    if (aep->ae_u.term.start != NULL)
-			out_str(aep->ae_u.term.start);
+		    if (t_colors > 1)
+		    {
+			if (aep->ae_u.cterm.fg_color)
+			    term_fg_color(aep->ae_u.cterm.fg_color - 1);
+			if (aep->ae_u.cterm.bg_color)
+			    term_bg_color(aep->ae_u.cterm.bg_color - 1);
+		    }
+		    else
+		    {
+			if (aep->ae_u.term.start != NULL)
+			    out_str(aep->ae_u.term.start);
+		    }
 		}
 	    }
 	}
@@ -7904,14 +7924,23 @@
 	    {
 		attrentry_T *aep;
 
-		if (t_colors > 1)
+		if (IS_CTERM)
 		{
 		    /*
 		     * Assume that t_me restores the original colors!
 		     */
 		    aep = syn_cterm_attr2entry(screen_attr);
-		    if (aep != NULL && (aep->ae_u.cterm.fg_color
-						 || aep->ae_u.cterm.bg_color))
+		    if (aep != NULL &&
+#ifdef FEAT_TERMTRUECOLOR
+			    (p_guicolors ?
+				(aep->ae_u.cterm.fg_rgb != INVALCOLOR ||
+				 aep->ae_u.cterm.bg_rgb != INVALCOLOR):
+#endif
+				(aep->ae_u.cterm.fg_color || aep->ae_u.cterm.bg_color)
+#ifdef FEAT_TERMTRUECOLOR
+			    )
+#endif
+			)
 			do_ME = TRUE;
 		}
 		else
@@ -7959,15 +7988,27 @@
 	    if (do_ME || (screen_attr & (HL_BOLD | HL_INVERSE)))
 		out_str(T_ME);
 
-	    if (t_colors > 1)
+#ifdef FEAT_TERMTRUECOLOR
+	    if (p_guicolors)
 	    {
-		/* set Normal cterm colors */
-		if (cterm_normal_fg_color != 0)
-		    term_fg_color(cterm_normal_fg_color - 1);
-		if (cterm_normal_bg_color != 0)
-		    term_bg_color(cterm_normal_bg_color - 1);
-		if (cterm_normal_fg_bold)
-		    out_str(T_MD);
+		if (cterm_normal_fg_gui_color != INVALCOLOR)
+		    term_fg_rgb_color(cterm_normal_fg_gui_color);
+		if (cterm_normal_bg_gui_color != INVALCOLOR)
+		    term_bg_rgb_color(cterm_normal_bg_gui_color);
+	    }
+	    else
+#endif
+	    {
+		if (t_colors > 1)
+		{
+		    /* set Normal cterm colors */
+		    if (cterm_normal_fg_color != 0)
+			term_fg_color(cterm_normal_fg_color - 1);
+		    if (cterm_normal_bg_color != 0)
+			term_bg_color(cterm_normal_bg_color - 1);
+		    if (cterm_normal_fg_bold)
+			out_str(T_MD);
+		}
 	    }
 	}
     }
@@ -7981,10 +8022,17 @@
     void
 reset_cterm_colors(void)
 {
-    if (t_colors > 1)
+    if (IS_CTERM)
     {
 	/* set Normal cterm colors */
+#ifdef FEAT_TERMTRUECOLOR
+	if (p_guicolors ?
+		(cterm_normal_fg_gui_color != INVALCOLOR
+		 || cterm_normal_bg_gui_color != INVALCOLOR):
+		(cterm_normal_fg_color > 0 || cterm_normal_bg_color > 0))
+#else
 	if (cterm_normal_fg_color > 0 || cterm_normal_bg_color > 0)
+#endif
 	{
 	    out_str(T_OP);
 	    screen_attr = -1;
@@ -8228,7 +8276,7 @@
 #ifdef FEAT_GUI
 	    !gui.in_use &&
 #endif
-			    t_colors <= 1);
+	    !IS_CTERM);
     for (row = start_row; row < end_row; ++row)
     {
 #ifdef FEAT_MBYTE
@@ -8911,6 +8959,9 @@
 #ifdef FEAT_GUI
 		|| gui.in_use
 #endif
+#ifdef FEAT_TERMTRUECOLOR
+		|| (p_guicolors && cterm_normal_bg_gui_color != INVALCOLOR)
+#endif
 		|| cterm_normal_bg_color == 0 || *T_UT != NUL));
 }
 
@@ -10242,6 +10293,9 @@
 #ifdef FEAT_GUI
 					    && !gui.in_use
 #endif
+#ifdef FEAT_TERMTRUECOLOR
+					    && !p_guicolors
+#endif
 					    );
 
     redraw_tabline = FALSE;
diff --git a/src/structs.h b/src/structs.h
index adee3e8..1775256 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -84,7 +84,9 @@
 # ifdef FEAT_XCLIPBOARD
 #  include <X11/Intrinsic.h>
 # endif
-# define guicolor_T int		/* avoid error in prototypes */
+# define guicolor_T long_u		/* avoid error in prototypes and 
+					 * make FEAT_TERMTRUECOLOR work */
+# define INVALCOLOR ((guicolor_T)0x1ffffff)
 #endif
 
 /*
@@ -911,6 +913,10 @@
 	    /* These colors need to be > 8 bits to hold 256. */
 	    short_u	    fg_color;	/* foreground color number */
 	    short_u	    bg_color;	/* background color number */
+# ifdef FEAT_TERMTRUECOLOR
+	    long_u	    fg_rgb;	/* foreground color RGB */
+	    long_u	    bg_rgb;	/* background color RGB */
+# endif
 	} cterm;
 # ifdef FEAT_GUI
 	struct
diff --git a/src/syntax.c b/src/syntax.c
index 31c1d0d..76a5976 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -33,10 +33,12 @@
     int		sg_cterm_fg;	/* terminal fg color number + 1 */
     int		sg_cterm_bg;	/* terminal bg color number + 1 */
     int		sg_cterm_attr;	/* Screen attr for color term mode */
-#ifdef FEAT_GUI
 /* for when using the GUI */
+#if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
     guicolor_T	sg_gui_fg;	/* GUI foreground color handle */
     guicolor_T	sg_gui_bg;	/* GUI background color handle */
+#endif
+#ifdef FEAT_GUI
     guicolor_T	sg_gui_sp;	/* GUI special color handle */
     GuiFont	sg_font;	/* GUI font handle */
 #ifdef FEAT_XFONTSET
@@ -97,10 +99,12 @@
 static int hl_has_settings(int idx, int check_link);
 static void highlight_clear(int idx);
 
-#ifdef FEAT_GUI
+#if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
 static void gui_do_one_color(int idx, int do_menu, int do_tooltip);
-static int  set_group_colors(char_u *name, guicolor_T *fgp, guicolor_T *bgp, int do_menu, int use_norm, int do_tooltip);
 static guicolor_T color_name2handle(char_u *name);
+#endif
+#ifdef FEAT_GUI
+static int  set_group_colors(char_u *name, guicolor_T *fgp, guicolor_T *bgp, int do_menu, int use_norm, int do_tooltip);
 static GuiFont font_name2handle(char_u *name);
 # ifdef FEAT_XFONTSET
 static GuiFontset fontset_name2handle(char_u *name, int fixed_width);
@@ -7333,8 +7337,8 @@
 	    for (idx = 0; idx < highlight_ga.ga_len; ++idx)
 		highlight_clear(idx);
 	    init_highlight(TRUE, TRUE);
-#ifdef FEAT_GUI
-	    if (gui.in_use)
+#if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
+	    if (USE_24BIT)
 		highlight_gui_started();
 #endif
 	    highlight_changed();
@@ -7788,10 +7792,16 @@
 		if (!init)
 		    HL_TABLE()[idx].sg_set |= SG_GUI;
 
-# ifdef FEAT_GUI
+# if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
 		/* In GUI guifg colors are only used when recognized */
 		i = color_name2handle(arg);
-		if (i != INVALCOLOR || STRCMP(arg, "NONE") == 0 || !gui.in_use)
+		if (i != INVALCOLOR || STRCMP(arg, "NONE") == 0
+#  ifdef FEAT_GUI
+			|| !(USE_24BIT)
+#  else
+			|| !p_guicolors
+#  endif
+		   )
 		{
 		    HL_TABLE()[idx].sg_gui_fg = i;
 # endif
@@ -7800,7 +7810,7 @@
 			HL_TABLE()[idx].sg_gui_fg_name = vim_strsave(arg);
 		    else
 			HL_TABLE()[idx].sg_gui_fg_name = NULL;
-# ifdef FEAT_GUI
+# if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
 #  ifdef FEAT_GUI_X11
 		    if (is_menu_group)
 			gui.menu_fg_pixel = i;
@@ -7825,10 +7835,10 @@
 		if (!init)
 		    HL_TABLE()[idx].sg_set |= SG_GUI;
 
-# ifdef FEAT_GUI
+# if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
 		/* In GUI guifg colors are only used when recognized */
 		i = color_name2handle(arg);
-		if (i != INVALCOLOR || STRCMP(arg, "NONE") == 0 || !gui.in_use)
+		if (i != INVALCOLOR || STRCMP(arg, "NONE") == 0 || !USE_24BIT)
 		{
 		    HL_TABLE()[idx].sg_gui_bg = i;
 # endif
@@ -7837,7 +7847,7 @@
 			HL_TABLE()[idx].sg_gui_bg_name = vim_strsave(arg);
 		    else
 			HL_TABLE()[idx].sg_gui_bg_name = NULL;
-# ifdef FEAT_GUI
+# if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
 #  ifdef FEAT_GUI_X11
 		    if (is_menu_group)
 			gui.menu_bg_pixel = i;
@@ -7997,7 +8007,9 @@
 	     * Need to update all groups, because they might be using "bg"
 	     * and/or "fg", which have been changed now.
 	     */
-	    if (gui.in_use)
+#endif
+#if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
+	    if (USE_24BIT)
 		highlight_gui_started();
 #endif
 	}
@@ -8068,6 +8080,10 @@
     cterm_normal_fg_color = 0;
     cterm_normal_fg_bold = 0;
     cterm_normal_bg_color = 0;
+# ifdef FEAT_TERMTRUECOLOR
+    cterm_normal_fg_gui_color = INVALCOLOR;
+    cterm_normal_bg_gui_color = INVALCOLOR;
+# endif
 #endif
 }
 
@@ -8118,9 +8134,11 @@
     vim_free(HL_TABLE()[idx].sg_gui_sp_name);
     HL_TABLE()[idx].sg_gui_sp_name = NULL;
 #endif
-#ifdef FEAT_GUI
+#if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
     HL_TABLE()[idx].sg_gui_fg = INVALCOLOR;
     HL_TABLE()[idx].sg_gui_bg = INVALCOLOR;
+#endif
+#ifdef FEAT_GUI
     HL_TABLE()[idx].sg_gui_sp = INVALCOLOR;
     gui_mch_free_font(HL_TABLE()[idx].sg_font);
     HL_TABLE()[idx].sg_font = NOFONT;
@@ -8140,7 +8158,7 @@
 #endif
 }
 
-#if defined(FEAT_GUI) || defined(PROTO)
+#if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR) || defined(PROTO)
 /*
  * Set the normal foreground and background colors according to the "Normal"
  * highlighting group.  For X11 also set "Menu", "Scrollbar", and
@@ -8149,44 +8167,78 @@
     void
 set_normal_colors(void)
 {
-    if (set_group_colors((char_u *)"Normal",
-			     &gui.norm_pixel, &gui.back_pixel,
-			     FALSE, TRUE, FALSE))
-    {
-	gui_mch_new_colors();
-	must_redraw = CLEAR;
-    }
-#ifdef FEAT_GUI_X11
-    if (set_group_colors((char_u *)"Menu",
-			 &gui.menu_fg_pixel, &gui.menu_bg_pixel,
-			 TRUE, FALSE, FALSE))
-    {
-# ifdef FEAT_MENU
-	gui_mch_new_menu_colors();
+#ifdef FEAT_GUI
+# ifdef FEAT_TERMTRUECOLOR
+    if (gui.in_use)
 # endif
-	must_redraw = CLEAR;
-    }
-# ifdef FEAT_BEVAL
-    if (set_group_colors((char_u *)"Tooltip",
-			 &gui.tooltip_fg_pixel, &gui.tooltip_bg_pixel,
-			 FALSE, FALSE, TRUE))
     {
-# ifdef FEAT_TOOLBAR
-	gui_mch_new_tooltip_colors();
+	if (set_group_colors((char_u *)"Normal",
+				 &gui.norm_pixel, &gui.back_pixel,
+				 FALSE, TRUE, FALSE))
+	{
+	    gui_mch_new_colors();
+	    must_redraw = CLEAR;
+	}
+# ifdef FEAT_GUI_X11
+	if (set_group_colors((char_u *)"Menu",
+			     &gui.menu_fg_pixel, &gui.menu_bg_pixel,
+			     TRUE, FALSE, FALSE))
+	{
+#  ifdef FEAT_MENU
+	    gui_mch_new_menu_colors();
+#  endif
+	    must_redraw = CLEAR;
+	}
+#  ifdef FEAT_BEVAL
+	if (set_group_colors((char_u *)"Tooltip",
+			     &gui.tooltip_fg_pixel, &gui.tooltip_bg_pixel,
+			     FALSE, FALSE, TRUE))
+	{
+#   ifdef FEAT_TOOLBAR
+	    gui_mch_new_tooltip_colors();
+#   endif
+	    must_redraw = CLEAR;
+	}
+#  endif
+	if (set_group_colors((char_u *)"Scrollbar",
+			&gui.scroll_fg_pixel, &gui.scroll_bg_pixel,
+			FALSE, FALSE, FALSE))
+	{
+	    gui_new_scrollbar_colors();
+	    must_redraw = CLEAR;
+	}
 # endif
-	must_redraw = CLEAR;
     }
 #endif
-    if (set_group_colors((char_u *)"Scrollbar",
-		    &gui.scroll_fg_pixel, &gui.scroll_bg_pixel,
-		    FALSE, FALSE, FALSE))
+#ifdef FEAT_TERMTRUECOLOR
+# ifdef FEAT_GUI
+    else
+# endif
     {
-	gui_new_scrollbar_colors();
-	must_redraw = CLEAR;
+	int		idx;
+
+	idx = syn_name2id((char_u *)"Normal") - 1;
+	if (idx >= 0)
+	{
+	    gui_do_one_color(idx, FALSE, FALSE);
+
+	    if (HL_TABLE()[idx].sg_gui_fg != INVALCOLOR)
+	    {
+		cterm_normal_fg_gui_color = HL_TABLE()[idx].sg_gui_fg;
+		must_redraw = CLEAR;
+	    }
+	    if (HL_TABLE()[idx].sg_gui_bg != INVALCOLOR)
+	    {
+		cterm_normal_bg_gui_color = HL_TABLE()[idx].sg_gui_bg;
+		must_redraw = CLEAR;
+	    }
+	}
     }
 #endif
 }
+#endif
 
+#if defined(FEAT_GUI) || defined(PROTO)
 /*
  * Set the colors for "Normal", "Menu", "Tooltip" or "Scrollbar".
  */
@@ -8299,24 +8351,6 @@
 }
 
 /*
- * Return the handle for a color name.
- * Returns INVALCOLOR when failed.
- */
-    static guicolor_T
-color_name2handle(char_u *name)
-{
-    if (STRCMP(name, "NONE") == 0)
-	return INVALCOLOR;
-
-    if (STRICMP(name, "fg") == 0 || STRICMP(name, "foreground") == 0)
-	return gui.norm_pixel;
-    if (STRICMP(name, "bg") == 0 || STRICMP(name, "background") == 0)
-	return gui.back_pixel;
-
-    return gui_get_color(name);
-}
-
-/*
  * Return the handle for a font name.
  * Returns NOFONT when failed.
  */
@@ -8439,6 +8473,52 @@
 
 #endif /* FEAT_GUI */
 
+#if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR) || defined(PROTO)
+/*
+ * Return the handle for a color name.
+ * Returns INVALCOLOR when failed.
+ */
+    static guicolor_T
+color_name2handle(char_u *name)
+{
+    if (STRCMP(name, "NONE") == 0)
+	return INVALCOLOR;
+
+    if (STRICMP(name, "fg") == 0 || STRICMP(name, "foreground") == 0)
+    {
+#if defined(FEAT_TERMTRUECOLOR) && defined(FEAT_GUI)
+	if (gui.in_use)
+#endif
+#ifdef FEAT_GUI
+	    return gui.norm_pixel;
+#endif
+#if defined(FEAT_TERMTRUECOLOR) && defined(FEAT_GUI)
+	else
+#endif
+#ifdef FEAT_TERMTRUECOLOR
+	    return cterm_normal_fg_gui_color;
+#endif
+    }
+    if (STRICMP(name, "bg") == 0 || STRICMP(name, "background") == 0)
+    {
+#if defined(FEAT_TERMTRUECOLOR) && defined(FEAT_GUI)
+	if (gui.in_use)
+#endif
+#ifdef FEAT_GUI
+	    return gui.back_pixel;
+#endif
+#if defined(FEAT_TERMTRUECOLOR) && defined(FEAT_GUI)
+	else
+#endif
+#ifdef FEAT_TERMTRUECOLOR
+	    return cterm_normal_bg_gui_color;
+#endif
+    }
+
+    return GUI_GET_COLOR(name);
+}
+#endif
+
 /*
  * Table with the specifications for an attribute number.
  * Note that this table is used by ALL buffers.  This is required because the
@@ -8514,8 +8594,15 @@
 			    && aep->ae_u.cterm.fg_color
 						  == taep->ae_u.cterm.fg_color
 			    && aep->ae_u.cterm.bg_color
-						 == taep->ae_u.cterm.bg_color)
-		     ))
+						  == taep->ae_u.cterm.bg_color
+#ifdef FEAT_TERMTRUECOLOR
+			    && aep->ae_u.cterm.fg_rgb
+						    == taep->ae_u.cterm.fg_rgb
+			    && aep->ae_u.cterm.bg_rgb
+						    == taep->ae_u.cterm.bg_rgb
+#endif
+						
+		       )))
 
 	return i + ATTR_OFF;
     }
@@ -8580,6 +8667,10 @@
     {
 	taep->ae_u.cterm.fg_color = aep->ae_u.cterm.fg_color;
 	taep->ae_u.cterm.bg_color = aep->ae_u.cterm.bg_color;
+#ifdef FEAT_TERMTRUECOLOR
+	taep->ae_u.cterm.fg_rgb = aep->ae_u.cterm.fg_rgb;
+	taep->ae_u.cterm.bg_rgb = aep->ae_u.cterm.bg_rgb;
+#endif
     }
     ++table->ga_len;
     return (table->ga_len - 1 + ATTR_OFF);
@@ -8671,7 +8762,7 @@
     }
 #endif
 
-    if (t_colors > 1)
+    if (IS_CTERM)
     {
 	if (char_attr > HL_ALL)
 	    char_aep = syn_cterm_attr2entry(char_attr);
@@ -8696,6 +8787,12 @@
 		    new_en.ae_u.cterm.fg_color = spell_aep->ae_u.cterm.fg_color;
 		if (spell_aep->ae_u.cterm.bg_color > 0)
 		    new_en.ae_u.cterm.bg_color = spell_aep->ae_u.cterm.bg_color;
+#ifdef FEAT_TERMTRUECOLOR
+		if (spell_aep->ae_u.cterm.fg_rgb != INVALCOLOR)
+		    new_en.ae_u.cterm.fg_rgb = spell_aep->ae_u.cterm.fg_rgb;
+		if (spell_aep->ae_u.cterm.bg_rgb != INVALCOLOR)
+		    new_en.ae_u.cterm.bg_rgb = spell_aep->ae_u.cterm.bg_rgb;
+#endif
 	    }
 	}
 	return get_attr_entry(&cterm_attr_table, &new_en);
@@ -8757,10 +8854,10 @@
 	aep = syn_gui_attr2entry(attr);
     else
 #endif
-	if (t_colors > 1)
-	aep = syn_cterm_attr2entry(attr);
-    else
-	aep = syn_term_attr2entry(attr);
+	if (IS_CTERM)
+	    aep = syn_cterm_attr2entry(attr);
+	else
+	    aep = syn_term_attr2entry(attr);
 
     if (aep == NULL)	    /* highlighting not set */
 	return 0;
@@ -8959,13 +9056,15 @@
 	return NULL;
     if (modec == 'g')
     {
-# ifdef FEAT_GUI
+# if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
+#  ifdef FEAT_GUI
 	/* return font name */
 	if (font)
 	    return HL_TABLE()[id - 1].sg_font_name;
+#  endif
 
 	/* return #RRGGBB form (only possible when GUI is running) */
-	if (gui.in_use && what[2] == '#')
+	if ((USE_24BIT) && what[2] == '#')
 	{
 	    guicolor_T		color;
 	    long_u		rgb;
@@ -8974,19 +9073,23 @@
 	    if (fg)
 		color = HL_TABLE()[id - 1].sg_gui_fg;
 	    else if (sp)
+#  ifdef FEAT_GUI
 		color = HL_TABLE()[id - 1].sg_gui_sp;
+#  else
+		color = INVALCOLOR;
+#  endif
 	    else
 		color = HL_TABLE()[id - 1].sg_gui_bg;
 	    if (color == INVALCOLOR)
 		return NULL;
-	    rgb = gui_mch_get_rgb(color);
+	    rgb = GUI_MCH_GET_RGB(color);
 	    sprintf((char *)buf, "#%02x%02x%02x",
 				      (unsigned)(rgb >> 16),
 				      (unsigned)(rgb >> 8) & 255,
 				      (unsigned)rgb & 255);
 	    return buf;
 	}
-#endif
+# endif
 	if (fg)
 	    return (HL_TABLE()[id - 1].sg_gui_fg_name);
 	if (sp)
@@ -9011,8 +9114,9 @@
 }
 #endif
 
-#if (defined(FEAT_SYN_HL) && defined(FEAT_GUI) && defined(FEAT_PRINTER)) \
-	|| defined(PROTO)
+#if (defined(FEAT_SYN_HL) \
+	    && (defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)) \
+	&& defined(FEAT_PRINTER)) || defined(PROTO)
 /*
  * Return color name of highlight group "id" as RGB value.
  */
@@ -9034,7 +9138,7 @@
     if (color == INVALCOLOR)
 	return 0L;
 
-    return gui_mch_get_rgb(color);
+    return GUI_MCH_GET_RGB(color);
 }
 #endif
 
@@ -9150,13 +9254,22 @@
      * For the color term mode: If there are other than "normal"
      * highlighting attributes, need to allocate an attr number.
      */
-    if (sgp->sg_cterm_fg == 0 && sgp->sg_cterm_bg == 0)
+    if (sgp->sg_cterm_fg == 0 && sgp->sg_cterm_bg == 0
+# ifdef FEAT_TERMTRUECOLOR
+	    && sgp->sg_gui_fg == INVALCOLOR
+	    && sgp->sg_gui_bg == INVALCOLOR
+# endif
+	    )
 	sgp->sg_cterm_attr = sgp->sg_cterm;
     else
     {
 	at_en.ae_attr = sgp->sg_cterm;
 	at_en.ae_u.cterm.fg_color = sgp->sg_cterm_fg;
 	at_en.ae_u.cterm.bg_color = sgp->sg_cterm_bg;
+# ifdef FEAT_TERMTRUECOLOR
+	at_en.ae_u.cterm.fg_rgb = GUI_MCH_GET_RGB(sgp->sg_gui_fg);
+	at_en.ae_u.cterm.bg_rgb = GUI_MCH_GET_RGB(sgp->sg_gui_bg);
+# endif
 	sgp->sg_cterm_attr = get_attr_entry(&cterm_attr_table, &at_en);
     }
 }
@@ -9307,10 +9420,12 @@
     vim_memset(&(HL_TABLE()[highlight_ga.ga_len]), 0, sizeof(struct hl_group));
     HL_TABLE()[highlight_ga.ga_len].sg_name = name;
     HL_TABLE()[highlight_ga.ga_len].sg_name_u = vim_strsave_up(name);
-#ifdef FEAT_GUI
+#if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
     HL_TABLE()[highlight_ga.ga_len].sg_gui_bg = INVALCOLOR;
     HL_TABLE()[highlight_ga.ga_len].sg_gui_fg = INVALCOLOR;
+# ifdef FEAT_GUI
     HL_TABLE()[highlight_ga.ga_len].sg_gui_sp = INVALCOLOR;
+# endif
 #endif
     ++highlight_ga.ga_len;
 
@@ -9349,7 +9464,7 @@
 	attr = sgp->sg_gui_attr;
     else
 #endif
-	if (t_colors > 1)
+	if (IS_CTERM)
 	    attr = sgp->sg_cterm_attr;
 	else
 	    attr = sgp->sg_term_attr;
@@ -9403,7 +9518,7 @@
     return hl_id;
 }
 
-#ifdef FEAT_GUI
+#if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
 /*
  * Call this function just after the GUI has started.
  * It finds the font and color handles for the highlighting groups.
@@ -9414,7 +9529,12 @@
     int	    idx;
 
     /* First get the colors from the "Normal" and "Menu" group, if set */
-    set_normal_colors();
+# if defined(FEAT_GUI) || defined(FEAT_TERMTRUECOLOR)
+#  ifdef FEAT_TERMTRUECOLOR
+    if (USE_24BIT)
+#  endif
+	set_normal_colors();
+# endif
 
     for (idx = 0; idx < highlight_ga.ga_len; ++idx)
 	gui_do_one_color(idx, FALSE, FALSE);
@@ -9430,12 +9550,17 @@
 {
     int		didit = FALSE;
 
-    if (HL_TABLE()[idx].sg_font_name != NULL)
-    {
-	hl_do_font(idx, HL_TABLE()[idx].sg_font_name, FALSE, do_menu,
+# ifdef FEAT_GUI
+#  ifdef FEAT_TERMTRUECOLOR
+    if (gui.in_use)
+#  endif
+	if (HL_TABLE()[idx].sg_font_name != NULL)
+	{
+	    hl_do_font(idx, HL_TABLE()[idx].sg_font_name, FALSE, do_menu,
 							    do_tooltip, TRUE);
-	didit = TRUE;
-    }
+	    didit = TRUE;
+	}
+# endif
     if (HL_TABLE()[idx].sg_gui_fg_name != NULL)
     {
 	HL_TABLE()[idx].sg_gui_fg =
@@ -9448,16 +9573,17 @@
 			    color_name2handle(HL_TABLE()[idx].sg_gui_bg_name);
 	didit = TRUE;
     }
+# ifdef FEAT_GUI
     if (HL_TABLE()[idx].sg_gui_sp_name != NULL)
     {
 	HL_TABLE()[idx].sg_gui_sp =
 			    color_name2handle(HL_TABLE()[idx].sg_gui_sp_name);
 	didit = TRUE;
     }
+# endif
     if (didit)	/* need to get a new attr number */
 	set_hl_attr(idx);
 }
-
 #endif
 
 /*
diff --git a/src/term.c b/src/term.c
index f6f8eae..82f8012 100644
--- a/src/term.c
+++ b/src/term.c
@@ -77,6 +77,9 @@
 static struct builtin_term *find_builtin_term(char_u *name);
 static void parse_builtin_tcap(char_u *s);
 static void term_color(char_u *s, int n);
+#ifdef FEAT_TERMTRUECOLOR
+static void term_rgb_color(char_u *s, long_u rgb);
+#endif
 static void gather_termleader(void);
 #ifdef FEAT_TERMRESPONSE
 static void req_codes_from_term(void);
@@ -382,9 +385,9 @@
 #  else
     {(int)KS_CRI,	"\033[%dC"},
 #  endif
-#if defined(BEOS_DR8)
+#  if defined(BEOS_DR8)
     {(int)KS_DB,	""},		/* hack! see screen.c */
-#endif
+#  endif
 
     {K_UP,		"\033[A"},
     {K_DOWN,		"\033[B"},
@@ -790,8 +793,10 @@
 #  endif
 # endif
 
-# if defined(UNIX) || defined(ALL_BUILTIN_TCAPS) || defined(SOME_BUILTIN_TCAPS) || defined(__EMX__)
+# if defined(UNIX) || defined(ALL_BUILTIN_TCAPS) || defined(SOME_BUILTIN_TCAPS) || defined(__EMX__) || defined(FEAT_TERMTRUECOLOR)
     {(int)KS_NAME,	"xterm"},
+# endif
+# if defined(UNIX) || defined(ALL_BUILTIN_TCAPS) || defined(SOME_BUILTIN_TCAPS) || defined(__EMX__)
     {(int)KS_CE,	IF_EB("\033[K", ESC_STR "[K")},
     {(int)KS_AL,	IF_EB("\033[L", ESC_STR "[L")},
 #  ifdef TERMINFO
@@ -939,6 +944,10 @@
     {TERMCAP2KEY('F', 'Q'), IF_EB("\033[57;*~", ESC_STR "[57;*~")}, /* F36 */
     {TERMCAP2KEY('F', 'R'), IF_EB("\033[58;*~", ESC_STR "[58;*~")}, /* F37 */
 # endif
+# ifdef FEAT_TERMTRUECOLOR
+    {(int)KS_8F,	IF_EB("\033[38;2;%lu;%lu;%lum", ESC_STR "[38;2;%lu;%lu;%lum")},
+    {(int)KS_8B,	IF_EB("\033[48;2;%lu;%lu;%lum", ESC_STR "[48;2;%lu;%lu;%lum")},
+# endif
 
 # if defined(UNIX) || defined(ALL_BUILTIN_TCAPS)
 /*
@@ -1257,6 +1266,171 @@
 
 };	/* end of builtin_termcaps */
 
+#if defined(FEAT_TERMTRUECOLOR) || defined(PROTO)
+# define RGB(r, g, b) ((r<<16) | (g<<8) | (b))
+struct rgbcolor_table_S {
+    char_u	*color_name;
+    guicolor_T	 color;
+};
+static struct rgbcolor_table_S rgb_table[] = {
+	{(char_u *)"black",	RGB(0x00, 0x00, 0x00)},
+	{(char_u *)"blue",	RGB(0x00, 0x00, 0xD4)},
+	{(char_u *)"brown",	RGB(0x80, 0x40, 0x40)},
+	{(char_u *)"cyan",	RGB(0x02, 0xAB, 0xEA)},
+	{(char_u *)"darkblue",	RGB(0x00, 0x00, 0x80)},
+	{(char_u *)"darkcyan",	RGB(0x00, 0x80, 0x80)},
+	{(char_u *)"darkgray",	RGB(0x80, 0x80, 0x80)},
+	{(char_u *)"darkgreen",	RGB(0x00, 0x80, 0x00)},
+	{(char_u *)"darkgrey",	RGB(0x80, 0x80, 0x80)},
+	{(char_u *)"darkmagenta",	RGB(0x80, 0x00, 0x80)},
+	{(char_u *)"darkred",	RGB(0x80, 0x00, 0x00)},
+	{(char_u *)"darkyellow",	RGB(0xBB, 0xBB, 0x00)},
+	{(char_u *)"gray",	RGB(0xC0, 0xC0, 0xC0)},
+	{(char_u *)"gray10",	RGB(0x1A, 0x1A, 0x1A)},
+	{(char_u *)"gray20",	RGB(0x33, 0x33, 0x33)},
+	{(char_u *)"gray30",	RGB(0x4D, 0x4D, 0x4D)},
+	{(char_u *)"gray40",	RGB(0x66, 0x66, 0x66)},
+	{(char_u *)"gray50",	RGB(0x7F, 0x7F, 0x7F)},
+	{(char_u *)"gray60",	RGB(0x99, 0x99, 0x99)},
+	{(char_u *)"gray70",	RGB(0xB3, 0xB3, 0xB3)},
+	{(char_u *)"gray80",	RGB(0xCC, 0xCC, 0xCC)},
+	{(char_u *)"gray90",	RGB(0xE5, 0xE5, 0xE5)},
+	{(char_u *)"green",	RGB(0x00, 0x64, 0x11)},
+	{(char_u *)"grey",	RGB(0xC0, 0xC0, 0xC0)},
+	{(char_u *)"grey10",	RGB(0x1A, 0x1A, 0x1A)},
+	{(char_u *)"grey20",	RGB(0x33, 0x33, 0x33)},
+	{(char_u *)"grey30",	RGB(0x4D, 0x4D, 0x4D)},
+	{(char_u *)"grey40",	RGB(0x66, 0x66, 0x66)},
+	{(char_u *)"grey50",	RGB(0x7F, 0x7F, 0x7F)},
+	{(char_u *)"grey60",	RGB(0x99, 0x99, 0x99)},
+	{(char_u *)"grey70",	RGB(0xB3, 0xB3, 0xB3)},
+	{(char_u *)"grey80",	RGB(0xCC, 0xCC, 0xCC)},
+	{(char_u *)"grey90",	RGB(0xE5, 0xE5, 0xE5)},
+	{(char_u *)"lightblue",	RGB(0xA0, 0xA0, 0xFF)},
+	{(char_u *)"lightcyan",	RGB(0xA0, 0xFF, 0xFF)},
+	{(char_u *)"lightgray",	RGB(0xE0, 0xE0, 0xE0)},
+	{(char_u *)"lightgreen",	RGB(0xA0, 0xFF, 0xA0)},
+	{(char_u *)"lightgrey",	RGB(0xE0, 0xE0, 0xE0)},
+	{(char_u *)"lightmagenta",RGB(0xF0, 0xA0, 0xF0)},
+	{(char_u *)"lightred",	RGB(0xFF, 0xA0, 0xA0)},
+	{(char_u *)"lightyellow",	RGB(0xFF, 0xFF, 0xA0)},
+	{(char_u *)"magenta",	RGB(0xF2, 0x08, 0x84)},
+	{(char_u *)"orange",	RGB(0xFC, 0x80, 0x00)},
+	{(char_u *)"purple",	RGB(0xA0, 0x20, 0xF0)},
+	{(char_u *)"red",		RGB(0xDD, 0x08, 0x06)},
+	{(char_u *)"seagreen",	RGB(0x2E, 0x8B, 0x57)},
+	{(char_u *)"slateblue",	RGB(0x6A, 0x5A, 0xCD)},
+	{(char_u *)"violet",	RGB(0x8D, 0x38, 0xC9)},
+	{(char_u *)"white",	RGB(0xFF, 0xFF, 0xFF)},
+	{(char_u *)"yellow",	RGB(0xFC, 0xF3, 0x05)},
+};
+
+    static int
+hex_digit(int c)
+{
+    if (isdigit(c))
+	return c - '0';
+    c = TOLOWER_ASC(c);
+    if (c >= 'a' && c <= 'f')
+	return c - 'a' + 10;
+    return 0x1ffffff;
+}
+
+    guicolor_T
+termtrue_mch_get_color(char_u *name)
+{
+    guicolor_T	color;
+    int		i;
+
+    if (*name == '#' && strlen((char *) name) == 7)
+    {
+	color = RGB(((hex_digit(name[1])<<4) + hex_digit(name[2])),
+	            ((hex_digit(name[3])<<4) + hex_digit(name[4])),
+	            ((hex_digit(name[5])<<4) + hex_digit(name[6])));
+	if (color > 0xffffff)
+	    return INVALCOLOR;
+	return color;
+    }
+    else
+    {
+	/* Check if the name is one of the colors we know */
+	for (i = 0; i < sizeof(rgb_table) / sizeof(rgb_table[0]); i++)
+	    if (STRICMP(name, rgb_table[i].color_name) == 0)
+		return rgb_table[i].color;
+    }
+
+    /*
+     * Last attempt. Look in the file "$VIM/rgb.txt".
+     */
+    {
+#define LINE_LEN 100
+	FILE	*fd;
+	char	line[LINE_LEN];
+	char_u	*fname;
+	int	r, g, b;
+
+	fname = expand_env_save((char_u *)"$VIMRUNTIME/rgb.txt");
+	if (fname == NULL)
+	    return INVALCOLOR;
+
+	fd = fopen((char *)fname, "rt");
+	vim_free(fname);
+	if (fd == NULL)
+	    return INVALCOLOR;
+
+	while (!feof(fd))
+	{
+	    int		len;
+	    int		pos;
+	    char	*color;
+
+	    fgets(line, LINE_LEN, fd);
+	    len = strlen(line);
+
+	    if (len <= 1 || line[len-1] != '\n')
+		continue;
+
+	    line[len-1] = '\0';
+
+	    i = sscanf(line, "%d %d %d %n", &r, &g, &b, &pos);
+	    if (i != 3)
+		continue;
+
+	    color = line + pos;
+
+	    if (STRICMP(color, name) == 0)
+	    {
+		fclose(fd);
+		return (guicolor_T) RGB(r, g, b);
+	    }
+	}
+	fclose(fd);
+    }
+
+    return INVALCOLOR;
+}
+
+    guicolor_T
+termtrue_get_color(char_u *name)
+{
+    guicolor_T	t;
+
+    if (*name == NUL)
+	return INVALCOLOR;
+    t = termtrue_mch_get_color(name);
+
+    if (t == INVALCOLOR)
+	EMSG2(_("E254: Cannot allocate color %s"), name);
+    return t;
+}
+
+    long_u
+termtrue_mch_get_rgb(guicolor_T color)
+{
+    return (long_u) color;
+}
+#endif
+
 /*
  * DEFAULT_TERM is used, when no terminal is specified with -T option or $TERM.
  */
@@ -1512,6 +1686,7 @@
 				{KS_CWP, "WP"}, {KS_CWS, "WS"},
 				{KS_CSI, "SI"}, {KS_CEI, "EI"},
 				{KS_U7, "u7"}, {KS_RBG, "RB"},
+				{KS_8F, "8f"}, {KS_8B, "8b"},
 				{(enum SpecialKey)0, NULL}
 			    };
 
@@ -2608,6 +2783,33 @@
 	OUT_STR(tgoto((char *)s, 0, n));
 }
 
+#if defined(FEAT_TERMTRUECOLOR) || defined(PROTO)
+    void
+term_fg_rgb_color(long_u rgb)
+{
+    term_rgb_color(T_8F, rgb);
+}
+
+    void
+term_bg_rgb_color(long_u rgb)
+{
+    term_rgb_color(T_8B, rgb);
+}
+
+#define RED(rgb)   ((rgb>>16)&0xFF)
+#define GREEN(rgb) ((rgb>> 8)&0xFF)
+#define BLUE(rgb)  ((rgb    )&0xFF)
+
+    static void
+term_rgb_color(char_u *s, long_u rgb)
+{
+    char	buf[7+3*3+2+1+1];
+
+    sprintf(buf, (char *)s, RED(rgb), GREEN(rgb), BLUE(rgb));
+    OUT_STR(buf);
+}
+#endif
+
 #if (defined(FEAT_TITLE) && (defined(UNIX) || defined(VMS) \
 	|| defined(MACOS_X))) || defined(PROTO)
 /*
diff --git a/src/term.h b/src/term.h
index 4e28486..4a7391c 100644
--- a/src/term.h
+++ b/src/term.h
@@ -87,10 +87,12 @@
     KS_CSV,	/* scroll region vertical */
 #endif
     KS_OP,	/* original color pair */
-    KS_U7	/* request cursor position */
+    KS_U7,	/* request cursor position */
+    KS_8F,	/* set foreground color (RGB) */
+    KS_8B	/* set background color (RGB) */
 };
 
-#define KS_LAST	    KS_U7
+#define KS_LAST	    KS_8B
 
 /*
  * the terminal capabilities are stored in this array
@@ -166,6 +168,8 @@
 #define T_RBG	(term_str(KS_RBG))	/* request background RGB */
 #define T_OP	(term_str(KS_OP))	/* original color pair */
 #define T_U7	(term_str(KS_U7))	/* request cursor position */
+#define T_8F	(term_str(KS_8F))	/* set foreground color (RGB) */
+#define T_8B	(term_str(KS_8B))	/* set background color (RGB) */
 
 #define TMODE_COOK  0	/* terminal mode for external cmds and Ex mode */
 #define TMODE_SLEEP 1	/* terminal mode for sleeping (cooked but no echo) */
diff --git a/src/version.c b/src/version.c
index 4599f88..bb32541 100644
--- a/src/version.c
+++ b/src/version.c
@@ -621,6 +621,11 @@
 #else
 	"-termresponse",
 #endif
+#ifdef FEAT_TERMTRUECOLOR
+	"+termtruecolor",
+#else
+	"-termtruecolor",
+#endif
 #ifdef FEAT_TEXTOBJ
 	"+textobjects",
 #else
@@ -749,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1770,
+/**/
     1769,
 /**/
     1768,
diff --git a/src/vim.h b/src/vim.h
index 9e2ab21..f503ebf 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1558,6 +1558,31 @@
 #define MSG_PUTS_LONG(s)	    msg_puts_long_attr((char_u *)(s), 0)
 #define MSG_PUTS_LONG_ATTR(s, a)    msg_puts_long_attr((char_u *)(s), (a))
 
+#ifdef FEAT_GUI
+# ifdef FEAT_TERMTRUECOLOR
+#  define GUI_FUNCTION(f)	    (gui.in_use ? gui_##f : termtrue_##f)
+#  define USE_24BIT		    (gui.in_use || p_guicolors)
+# else
+#  define GUI_FUNCTION(f)	    gui_##f
+#  define USE_24BIT		    gui.in_use
+# endif
+#else
+# ifdef FEAT_TERMTRUECOLOR
+#  define GUI_FUNCTION(f)	    termtrue_##f
+#  define USE_24BIT		    p_guicolors
+# endif
+#endif
+#ifdef FEAT_TERMTRUECOLOR
+# define IS_CTERM		    (t_colors > 1 || p_guicolors)
+#else
+# define IS_CTERM		    (t_colors > 1)
+#endif
+#ifdef GUI_FUNCTION
+# define GUI_MCH_GET_RGB	    GUI_FUNCTION(mch_get_rgb)
+# define GUI_MCH_GET_COLOR	    GUI_FUNCTION(mch_get_color)
+# define GUI_GET_COLOR		    GUI_FUNCTION(get_color)
+#endif
+
 /* Prefer using emsg3(), because perror() may send the output to the wrong
  * destination and mess up the screen. */
 #ifdef HAVE_STRERROR