Lexadecimal - colour codes with meaning
lexadecimal.com
lexadecimal.com
I think it would be improved by having a cleverer colour-based sorting algorithm. At the moment, you choose one parameter (H, S or V) to sort by, and the others have no effect at all, and it looks a bit too random.
Here's one toy example of what I think is a more natural-looking order of colours: http://i.imgur.com/xjh97.png (I took red<<1, green<<2 and blue, and interleaved their bits). Better still might be to sort by position along a Hilbert-curve traversal of the RGB cube or HSL space or something, but I couldn't work out how to do that in 5 minutes so didn't bother :-).
Like this? http://corte.si/posts/code/hilbert/portrait/index.html
My favorite is probably the classic 0xDEADF00D, but I also like 0xCAFEBABE as used by Java class files, and 0xFEEDFACE since it's just funny.
True, these mostly stand out in hex, but they would be "very large" in decimal which often stands out pretty well.