My GT is very similar in size and when I first added him was quite light in colour however from day one it was quite dominant and had a bit of a hump, it went through a spell of eating very little and looking quite pale but after couple of weeks started to pick on fish way bigger than it.

I definitely agree with the other posts regarding fish adapting and blending in with the colours around them, my tank is in the wall so both sides allow light through so I often see a lot of changes in the colouring depending on time of day etc in my tank the colour changing king is my chocolate chiclid who literally changes colour all the time.

I definitely agree with the other posts regarding fish adapting and blending in with the colours around them, my tank is in the wall so both sides allow light through so I often see a lot of changes in the colouring depending on time of day etc in my tank the colour changing king is my chocolate chiclid who literally changes colour all the time.