The dark one is a young, blueface male. The growling noise is the only noise I'm absolutely positive I've never had a female make, so the noise alone is actually enough to sex him by. But he also has dark red feathers on his belly (only faintly visible from your pics, but they're there) and blue feathers on his sides, and those are male colors. The other one is a red breasted female.
Omg! Thank you!
You just confirmed my suspicions!
Haha and the little girl that helped me actually sexed them the other way around! But the more research I was doing I was thinking that she had the, backwoArds or I had two females
I have better succes keeping them in pairs. I've tried with more females but unless the enclosure is an aviary the females tend to start chasing each other after a while. And you definitely shouldn't try to add more males, even in a big enclosure, that's asking for trouble.
That could work out, but keep a close eye on them for aggression, and give them more cover to get away from each other. Buttons like to hide in brush, put some branches in there.