patch 7.4.1799
Problem:    'guicolors' is a confusing option name.
Solution:   Use 'termguicolors' instead. (Hirohito Higashi)
diff --git a/src/structs.h b/src/structs.h
index 1775256..50901ac 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -85,7 +85,7 @@
 #  include <X11/Intrinsic.h>
 # endif
 # define guicolor_T long_u		/* avoid error in prototypes and 
-					 * make FEAT_TERMTRUECOLOR work */
+					 * make FEAT_TERMGUICOLORS work */
 # define INVALCOLOR ((guicolor_T)0x1ffffff)
 #endif
 
@@ -913,7 +913,7 @@
 	    /* 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
+# ifdef FEAT_TERMGUICOLORS
 	    long_u	    fg_rgb;	/* foreground color RGB */
 	    long_u	    bg_rgb;	/* background color RGB */
 # endif