I was browsing around the internet and came across Iconza by turbomilk. As it seemed rather nice and my Framework Detector Firefox add-on sniffed out mootools, I had a look at the source.

It uses what looks like a colour picker plugin for mootools called mooRainbow. Nice to have in your toolkit, you never know. Iconza’s png trickery is not too shabby either, nice site (as you’d expect from Turnomilk anyway).