Like many of the online interactive color visualization and color picking utilities, ColorJack offers multiple interfaces with different options and capabilities.
The most interesting of these, and most popular of the ColorJack options, is their Color Sphere, or Color Theory Visualizer (image above, top). More than simply a color picker, this displays the secondary, tertiary and multiple other colors in some of the most common color harmony relationships (complimentary, split-complementary, triadic, etc.); and allows you to dynamically see their relationship in the color space as you move the chosen color within the sphere, or adjust one of the color’s characteristics in the bars to the right of the sphere.
Another interface is the Color Galaxy (above, second down); it displays the color wheel position of various named colors, displayed from a color index chosen from a drop-down menu at top left. This would be more useful to painters if there were a choice traditional painters pigments, though you will find some of them in the “CNE” choice. There are choices for Munsell’s catalog listings, though you need to be familiar with his cryptic indexing system for it to be particularly useful.
Navigation between the sections is inconsistent, but you’ll find interesting features if you’re willing to flip around and investigate.