Anyone interested in a (paid) project to develop a simple version of this in PHP? I could use this kind of feature for another project I'm working on.

If interested, ping me.

this is really clever... source code?!

Yeah I know! I read this ages ago actually... I remember my jaw dropping at how cool this is. :D

I've been thinking of hacking up some code to figure out a "good" set of colours given an image. I'll let you know if I figure it out. :)

Source wouldn't help that much. You'd need to implement it yourself for whatever image library you have anyway.

It's not that hard:

a: find the corner colors

b: find 2 of the most saturated common colors in the logo

c: calculate luminance of your chosen color, to pick black or white text

Defining 'common' in b is probably the hardest part.