there are a few repainted... but most of the "MSP"s that you see that aren't one of the stock colors are non-MSPs with MSP kits on them. I don't mean to sound purest, but what would be the sense in changing the color of a limited production car?
Edit: if you have a reason for painting it (lots of chips, accident, hail damage, etc) I guess I could see it... but for the most part... a GOOD paint job is expensive and I just don't see it as worth it for what you end up getting. if the color is that important to you, buy something thats already a color you like.