hm... My specimen doesn't appear to have pink or yellow rear.... It looks kinda pale or washed out. I wonder if mine is still too young to show coloration.
Once the little chap settles into his/her's new environment and with some good feeds, it might colour up. If not then i wouldn't worry about it. Not all of them carry the colours.
Yes, Hlie - it's that double band beneath the dorsal that's the giveaway. I'd wager it's cf. balteata as well. And yes, these somehow ended up with the totally inappropriate market name "sumo loach." It just doesn't mean anything.