If they got sickness or bloodlice than the colour disapears yes :yes: .
If they young and comb grows than from pink to red means they about able to lay eggs.
If adult chicken’s comb becomes bloodred en enlarge they are broody 😉 .
Be aware of bloodlice when summer kicks in. You will not see them at daytime, they are nightcreatures and come out after sunset. They are bloodsucking little vampirelice that will slowly suck the life out of the chickens. Litteraly :death: almost without any other sign than the chicken feeling sad and colour fading in combs. They look like very tiny little dark greycoloured spiders.