Oh yes much more vibrant colors will appear on the males as they mature. They both do kinda look like males. But if you grow them out a bit (if you have the space) you could get more money/store credit for them....if you decide to trade them in.
And you will get to see how nice they get.
Peacocks are one of those things that are kinda cool to buy like this and see what they grow up to be, IMO.
I'd say if you had the space and enough females to the males, then yes fairly easy to breed. I find the hard part to be getting the fry out alive, as i'm not good at stripping fish or getting them out before the others eat them