In yall humble opinion is it likely that they will remain looking like the video and picture into adulthood? I only really have interest if it keeps those colors.
There is genuinely not enough information to say. You would have to make an informed guess.
You can try considering these facts:
1. This fish likely does not exceed 8”, if you can find out the size of these fish, you can gauge their age. If they are 6” I would guess they would keep the red fins into adulthood
2. The photo I provided from “bkok fish”. The fish seem to be big and have green bars but we cannot know for sure given the context of the source.
3. The video I provided from Cesar Schmitke which was recorded in Misiones. If those fish are C. sp. Uruguay, they would in fact be adults as they were rearing fry. And in that video, they are greener and do not have red fins. But I am not 100% positive on the identity of those fish.
4. Crenicichla (lacustria) empheres, the closest species to this, are incredible fish but do not have the most magnificent coloration.
5. A bit unrelated but personally, I don’t think it is good to buy from Predatory Fins.