In that case I think you will have to wait a while before any-one could say with much confidence either way.
If it's a male, he will gradually become more colourful, and grow more pointed tips to his dorsal and anal fins.
If it's a female, she will grow plumper, and her colour won't change very much, until she is ready to breed, when it gets more intense, but not nearly as deep as the males.
hth