thanks Eric.
I shoud've bought a few more the same day when I picked up this guy. couple weeks later when I went back the whole batch was gone. there were few nice ones but this one was the best out of them. and price was great too for wild imports at this size, shape and color.
it's actually getting darker now (the picture was taken when I first got the fish almost 2 months ago), more like a dark green.
I hope it gets to keep it but it'll probably fade away as you said.