lol does he live in a trash can?
lots of fish change color with temperment, my late pleco (i probly said THE word too much) changed from speckled to blotchy to pitch black, all depending on what it was sitting on (black- the background, blotchy- the rocks in my tank, speckled- the gravel)
it was really cool to watch
my serpae (sp?) tetras will also change color with their mood as well as my black tetras