Sorting colors...

Sorting colors ... is much more difficult than you might imagine!  Years ago I worked on a compression scheme for a remote control product that was specific to color displays.  My objective was to use 8 bit palette to represent a screen snapshot when the screen was using 24 bit color.  This is very similar to the color sorting problem: I needed to identify 256 colors that were as close as possible to all the colors used on the 24 bit screen.  Knowing how “close” two colors were to each other was the key.  As the linked article details, this isn't the simple numeric problem you might imagine – how we perceive colors is quite different than how we represent colors in standard numeric encoding schemes (RGB, HSL, CMYK, etc.)...