This window, labelled Simple, shows you all pre-defined named system colors, as shown in . For each color, it shows a small sample, Red, Green and Blue (RGB) values, and color name. These colors can not be changed by the user (for advanced users, we note that these colors are defined in a special configuration file, rgb.txt, located in X11 library directory, usually /usr/lib/X11R6/lib/X11).
As was mentioned before, you can drag any of the color rectangles to GNOME Panel, GNOME Terminal, and many other GNOME applications windows to change their background colors.
By default, the colors are listed alphabetically by name, which is indicated by a small downward triangle next to the label Name. As with all GNOME applications, you can reverse the order by clicking on the word Name once. You can also have the list ordered by the RGB values, by clicking on Value, though it seems to be of little use.
You can change the default width of Color, Search and Name fields by dragging the separator between these fileds with the left mouse button.