What did you change so that his colors became brighter?
I think the biggest difference was he settled in. He just became more comfortable in the tank. I keep the temperature at 84° but has been suggested to move it up to 86.
Another factor may be that I attempted to introduce a female. I kept them separated and then learned that it was a male. So they have only been able to see each other through the divider with no interaction. Haven’t noticed so much of a color change since then but his head hump has definitely grown.
The other male will be going back soon didn’t want to make too many changes to quickly so he didn’t stress out.