okay so few months back I bought a few cichlids a Malawi Blue Dolphin, what I believe to be an OB zebra, and 1 I'm having a hard time classifing.i asked mfk some think its a lab x hongi. He was partly yellow and partly purple...well more turning purple. But a few weeks later that all stopped, now he is a dirty yellow color.. Why did he stop his color change, and how can I get it back?