Hue-Saturation-Luminance Color Selector Sliders change hue, saturation or luminance. Buttons select which dimension you want represented in the color panel. Cross-hairs can be used to select specific color in the color panel.
Completed! And this time, it's actually useful. I'm pleased with the results for two reasons. 1. It turned out just the way I envisioned it. 2. This excercised forced me to learn various programming concepts. Classes, arrays, class inheritance, GUI, text display, methods. Linking it all together is the satisfying part. When you change the position of the hue slider, it affects all the other elements: the position of the plane in the cube, the color values in the color plane (or cross-hair position), the colors within the saturation and luminance sliders, and of course, the selected color. Hopefully, this will be the proper shove-off I'll need to propel me further with visual programming.
Source code: hsl09d. Built with Processing