Rooster comb gets pale everynight

[Skywolfe10]

Lately my 4-5 month old Belgian Duccle roo has been getting a pale comb. But oddly enough its when hes going to bed. In the morning when I let him out hes got a normal color and acts normal. Then when I check on him at night an hour after theyve been in hes super pink. No one else is having these issues but him

 

[oldhenlikesdogs]

This time of year hormones are lower, so maybe between his age and time of year his comb isn't as bright. It also looks black along the front?