They are bifas, based on the red dots that distinct it from the solid color of melanura/synspillum. Yours have good color quality. How large are yours? Mine don' t color up until 4 to 5 inch, much later than melanura. See pcs of my juvies and adults
https://www.monsterfishkeepers.com/...liari-10-nj-md-pa-pickup.678051/#post-7624763
Your melanura don't look synspillum based on the body shape and early coloring. The dark patches are variable and moody, sometime turns up to fill the entire body and this is why it is named melanomas. It's strange that dominant fish is darker and less colorful.