How long have you had it, and how big is it?
Females, IME, are generally less colorful, but both sexes, in comparison to other cichlid species, are very colorful. Males will have a red trim on dorsal and tail. The black spot on the belly is usually not as dark. The only real indication I can see is the lack of red trim and rounded fins.
However, if the fish is young, the fins may lengthen into points (or get sharper points), and the red may brighten. If the fish is new, it may be simply be pale. I don't know if it's your camera, but I've never had a GT look so brown/maroon...