Hate the Blue, it is much too dull looking as opposed to the M5's Matte Blue, it looks like powder blue. It looks as if their is no sheen and it is a Flat Blue as compared to the M5's Semi-Gloss...
Also I like the Silver but really Silver Frost? They couldn't have thought of anything remotely different, it's clear that its a slight change to BMW's Frozen Gray. They should just call the Matte Colours Stealth <insertcolourhere> </instercolourhere> so Stealth Silver or Blue. Matte Black would have been a much more attractive choice than that blue...
It's a step in the right direction though, for Cadillac to be a true competitor they will have to introduce customization to their cars, the ATS has started with the multiple interior colours, but they need to have a line of custom paints that they charge $5,000+ for.
You will rarely see another M3 like this just driving around because of BMW Individual:
But the big thing is it's a step in the right direction!