I have a hold back agouti male. Chubby and very sweet. He has always preferred to be with a human than a rat. I see the craziness with any color. The siamese seem to be the most flighty and afraid. The light orange ones (color name?) are either shy or mean and bite. The black hooded ones seem to be the most hyper and the most likely to chew.

The black eyed grey's and ruby eyed blues always seem the most calm and sweet. I know they are all different though. My observations may not be anywhere close to others observations.