Correct me if I'm wrong here GXPinKC but according to my dealer the aggressive GXP was the fastest of the lot, and I doubt that a dealer would have lied. 
I believe the Mean GXP has more horsepower and that was a very Brazen comment, but there is one color that is very Cool, this is getting a bit Deep, most of it is Pure BS.
Thanks Sol Asylum and lil goat, I do agree with your assessment. That's why I went with the "Aggressive", because my dealer, (salesman) told me the same thing stating that the "Aggressive" was the fastest of the lot, so I'm sure he was not lying, and having previously owned an "Aggressive" '95 Pontiac Firebird Formula (back then the color was called "Victory Red" by GM), I knew that this salesman knew what he was talking about, because the thing was faster than a "Cool" mountain breeze and also had a "Wicked" look to it.
I immediately bonded with the Pontiac Solstice car salesman and grew to trust his statements. As I got to know him, it became obvious that his wife was somewhat "Aggressive" as she kept winking at me, and I thought that was somewhat "Brazen" and I thought she was trying to flirt with me. It made me feel "Envious". However my salesman said that she had an eye problem that caused her to blink. So, I was relieved that she was "Pure" after-all.
However, I found the Finance Manager to be a "Sly" fox and also "Mean" because he wanted to go "Deep" into my pockets and he would not budge from his price. To me that was indeed "Mysterious"!
I found GM's marketing of the color names to be fun and unique in the industry. It is my prayer and hope that they will be able to survive and prosper in the future. Marcs Carbon Flash and owner of a 2008 Sky redline SE, I hope the above explanation sheds some light on the "color names" that the marketing division of Pontiac came up with to promote the Pontiac Solstice. It was indeed, genius!
GXPinKC
Ron