I didn't realize these where the two you got from me.
The big one is a confirmed male that has flashed and fathered most of my babies.
He is also very concave.
The smaller, brightly colored one my wife reported it mounting a female. I've never seen it flash. He also looks male.
So, big one is confirmed and small one is very ,very likely also male.
Maybe more traits will be obvious as they mature.