diff --git a/src/syntax.c b/src/syntax.c
index 4e35a6c..e68090d 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -9261,8 +9261,8 @@
 	at_en.ae_u.cterm.fg_color = sgp->sg_cterm_fg;
 	at_en.ae_u.cterm.bg_color = sgp->sg_cterm_bg;
 # ifdef FEAT_TERMGUICOLORS
-	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);
+	at_en.ae_u.cterm.fg_rgb = GUI_MCH_GET_RGB2(sgp->sg_gui_fg);
+	at_en.ae_u.cterm.bg_rgb = GUI_MCH_GET_RGB2(sgp->sg_gui_bg);
 # endif
 	sgp->sg_cterm_attr = get_attr_entry(&cterm_attr_table, &at_en);
     }
diff --git a/src/version.c b/src/version.c
index 714a6d9..75e692d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1812,
+/**/
     1811,
 /**/
     1810,
diff --git a/src/vim.h b/src/vim.h
index 5d98a4c..a5d05a1 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1561,14 +1561,23 @@
 #ifdef FEAT_GUI
 # ifdef FEAT_TERMGUICOLORS
 #  define GUI_FUNCTION(f)	    (gui.in_use ? gui_##f : termgui_##f)
+#  define GUI_FUNCTION2(f, pixel)   (gui.in_use \
+				    ?  ((pixel) != INVALCOLOR \
+					? gui_##f((pixel)) \
+					: (long_u)INVALCOLOR) \
+				    : termgui_##f((pixel)))
 #  define USE_24BIT		    (gui.in_use || p_tgc)
 # else
 #  define GUI_FUNCTION(f)	    gui_##f
+#  define GUI_FUNCTION2(f,pixel)    ((pixel) != INVALCOLOR \
+				     ? gui_##f((pixel)) \
+				     : (long_u)INVALCOLOR)
 #  define USE_24BIT		    gui.in_use
 # endif
 #else
 # ifdef FEAT_TERMGUICOLORS
 #  define GUI_FUNCTION(f)	    termgui_##f
+#  define GUI_FUNCTION2(f, pixel)   termgui_##f((pixel))
 #  define USE_24BIT		    p_tgc
 # endif
 #endif
@@ -1579,6 +1588,7 @@
 #endif
 #ifdef GUI_FUNCTION
 # define GUI_MCH_GET_RGB	    GUI_FUNCTION(mch_get_rgb)
+# define GUI_MCH_GET_RGB2(pixel)    GUI_FUNCTION2(mch_get_rgb, (pixel))
 # define GUI_MCH_GET_COLOR	    GUI_FUNCTION(mch_get_color)
 # define GUI_GET_COLOR		    GUI_FUNCTION(get_color)
 #endif