[GRASS5] Hex equivalents of grass colors?

[Glynn Clements]

Cedric Shock wrote:

> Michael,
> 
> > Is there some kind of lookup available for the hex equivalent of standard
> > grass colors (red, violet, etc)? Lacking that, is there an RGB lookup that
> > I could translate to hex?
> 
> This is information is on my wish list too. I found it in: 
> http://freegis.org/cgi-bin/viewcvs.cgi/grass6/lib/gis/color_str.c
> 
>     {"white",   255, 255, 255},
>     {"black",     0,   0,   0},
>     {"red",     255,   0,   0},
>     {"green",     0, 255,   0},
>     {"blue",      0,   0, 255},
>     {"yellow",  255, 255,   0},
>     {"magenta", 255,   0, 255},
>     {"cyan",      0, 255, 255},
>     {"aqua",    100, 127, 255},
>     {"grey",    127, 127, 127},
>     {"gray",    127, 127, 127},
>     {"orange",  255, 127,   0},
>     {"brown",   180,  75,  25},
>     {"violet",  255,   0, 255},
>     {"indigo",    0, 127, 255}

However, this doesn't exactly match the colours used by the display
drivers. Both the PNG and X drivers use:

	LIB_assign_standard_color(RED,     DRV_lookup_color(255,   0,   0));
	LIB_assign_standard_color(ORANGE,  DRV_lookup_color(255, 128,   0));
	LIB_assign_standard_color(YELLOW,  DRV_lookup_color(255, 255,   0));
	LIB_assign_standard_color(GREEN,   DRV_lookup_color(  0, 255,   0));
	LIB_assign_standard_color(BLUE,    DRV_lookup_color(  0,   0, 255));
	LIB_assign_standard_color(INDIGO,  DRV_lookup_color(  0, 128, 255));
	LIB_assign_standard_color(VIOLET,  DRV_lookup_color(255,   0, 255));
	LIB_assign_standard_color(BLACK,   DRV_lookup_color(  0,   0,   0));
	LIB_assign_standard_color(WHITE,   DRV_lookup_color(255, 255, 255));
	LIB_assign_standard_color(GRAY,    DRV_lookup_color(175, 175, 175));
	LIB_assign_standard_color(BROWN,   DRV_lookup_color(180,  77,  25));
	LIB_assign_standard_color(MAGENTA, DRV_lookup_color(255,   0, 128));
	LIB_assign_standard_color(AQUA,    DRV_lookup_color(100, 128, 255));

The main differences are for magenta and grey. The driver's magenta is
definitely wrong, as magenta is supposed to be one of the corners of
the RGB cube; maybe those values should be used for violet?

-- 
Glynn Clements <glynn at gclements.plus.com>