red cap oranda question

I have this red cap oranda for about three years now. When it was very
young it had the red brains on the outside of the head look to it. After I
had it a few months it lost this feature, and to this day it still has the
red head, but it is flat. Every picture I see of them, they are like he was
when he was young. Is there a nutrient that keeps this feature that I'm
missing.