There is an exception for every rule, but I would say your JD is fine. Often the dominant fish has the most vivid color. It is part mating, threat and bravado displaying. One of my JD is the least dominant fish in the tank and his color is quite light. He gets a little darker right before he sneaks up on the dominant JD and hits him from behind. Then he gets lighter and runs like...
The dominant JD is very dark with great color, until it is threatened by the Texas at which time he lightens up.