xcolorsel(1x) on Linux
The text 3065071f4cb8, as Debian 3.1 (Sarge), Debian 3.0 (Woody), Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 2.0 (Hamm), Debian 1.3 (Bo), Debian 1.2 (Rex) shipped it. The page shows this text now.
display contents of rgb.txt files together with color probes.