They can be vibrant colors with bars or dark with bars. Each say different moods; good and bad.. Bars is a sign of something exciting going on in the fish's head. Breeding, fighting, running away, ect. Depends what colors shown with the bars
Mine is barred when stressed, but also when challenging another fish / matching up with another fish. When relaxed he loses the bars, but anytime he gets excited or scarred he bars up.
I'd say it's more likely that pale/drab coloration represents stress. Darkened bars usually signals aggression, dominance, breeding behavior, defending a territory etc.
My female is barred when spawning and showing dominance, which is basically all the time. My male is barred when guarding. When either are pale or washed out, something is amiss in the tank.
Here's with fry for the first 3 pics. Last pic is no fry but pre-spawn.
Most of my barred up fry turn out to be the alphas in their perspective tanks.