Gimp color selector - great tool
I was trying to create some web colors and stumbled into a tool within Gimp (another reason to try Linux). It consists of a triangle rotating within a color wheel. The triangle points at the color hue. Within the triangle are combinations of intensity and saturation. It provides a large selection of colors, all of which are the same hue.

Since it is a triangle, it also allows for quick selection of thirds, a technique often used in web design. Simply grab the circle on the ring with your mouse and rotate until it is pointing where one of the other corners of the triangle is pointing.
Or, just point the triangle opposite the color, and you get a wide selection of colors that are the exact compliment. But you are not limited to the brilliant, intense version of the compliment. The example below was created by pointing the triangle to the left, then selecting different options until the desired contrast and saturation level was found.

This is a useful tool for developing color studies before commiting paint to canvas.
- the MuseTags: Linux