This is "Diablo", one of my "creations" from a long time ago.

His color is more like a chameleon, it changes from red to blue; when he's mad he's mostly red, when he's calm he's mostly blue. His color switches in a marble-like way, waving and shimmering to the different color.

In this picture he's having a "moody" day, he's a little pissed but is on the way to calming down. He's moody most of the time, actually.