All the colours! (#colors).
This is another #archaic #x11 program, which follows on from #xmcolor in many respects, and one which I recall using a lot!
#xcolors is both a visualisation of all the colours availabe (via rgb.txt) as well as a means of seeing how background and foreground colours interact -- which is the main purpose of this program.
Originally written in 1989 by Paul Vixie (of cron(1) fame), the version here is written by Stephen Gildea, in 1991.
To this day, I did not have to modify the code, everything just worked!
It's a program written using Xt (the X Intrinsics Library).
Here are all the colours in their glory!
#colors #archaic #x11 #xmcolor #xcolors