Xcolorsel

X utility to translate rgb values into X color names

xcolorsel is a X-Utility based on this widget that allows you to display such files /usr/lib/X11/rgb.txt by default together with tiles showing how the color looks on your screen. Also a programmer may like with xfontsel cut the color names/definitions in various formats Colorformats and formats for resourcefiles or C-sources und paste them directly in his source codes.