Here's a how-to a wrote a while ago.. i'm going to write a few more as people request them.. just lemme know if you need a particular one? ...or let me know if i need to clarify anything, thx.

http://www.roofles.com/colorizing/

A better...IMO...tutorial on recoloring your bike...leaves it open to gradients/more complicated schemes.

http://www.velocitydesign.net/tutorials.html