Before everyone gets too carried away with colour choices, let me just tell you all that I have a simple LEGO-OH that flypig designed. It's really cool and I like it a lot, but I got a blue one (made by Shapeways) and here's the thing:

After having it in my pocket for a few months the colour is starting to come off. I thing Dirkvl has already pointed this out, but all plastics (except for alumide I guess) are just surface coated white prints it seems. So the colour does wear off, at least on my piece.

Something for you all to consider before deciding on what colour to choose.

Edit: I'm in no way criticising Dirkvl, just wanted to make that very clear! I'm extremely impressed with what he and the rest of the team has come up with. If anything, I'm a bit disappointed in the way Shapeways markets their available colours...