Looking good and healthy!
Nice fish. I'va always wanted one but I fear it would need it's own tank in the long run.
Marty looks like he could use some pumping up...head looks like it could be lot bigger.
To pump him up...first, give him little more room, bump temps up to about 86 so he'll be more active & have a big appetite, give him protein rich food & I'd throw another male on other side of that tank to get him pissed off & he'll really want to show off his colors....that's what I'd do to pump him up...LOL!