My rustys aren't all semi-purple. They're very young and out of my 5, only two have a purplish sheen. And today one of the bigger ones I found out is holding! So baby Rustys en route soon! Mom is all brown and about 2" long right now, I'm hoping the dad is one of the purplish ones, which I think are males in show dress.
Also, my Acei are pretty big (2.5"-3") and are still not spawning, but I just re-arranged the tank and did a water change last week so maybe they need some time to get used to it, or maybe I just got all dudes.