I would suggest that you don't buy yumas that look unhealthy. Ime they are not as hardy in the general sense as some would have you believe. Yes there will be many specimens that are super healthy and hardy but not nearly all. First issue is the light thing, too much will kill them, especially initially (first few months) and while acclimating (first few days). The next issue is the health of many of the ones being sold by the vendors. You wouldn't even believe the stories I could tell you about yumas dying after only a few weeks waiting in a vendors tank, some of the best vendors! Imagine if these same yumas were shipped, they would have def died from that stress considering they can't survive in the vendors tanks who are supposed to have the best systems. The thing to look for is the oral cone... is it cone shaped or is it gaping real bad... is it just a hole... is it just flat... if the mouth is a cone sticking out and its closed thats a good sign. Ask the vendor if the yuma is wild or aquacultured. Aquacultured yumas do well. Ime a large percentage of wild yumas die, like maybe 30 percent or more. Some of the color combinations do better, some worst. And remember thats not just in my tank I believe its the skeleton in the closet with that species and I will open the door on it.
I do have many many yumas that are crazy cool and I can't kill if I tried, but the larger wild ones that look the coolest have a lower survivability and I would stay away from them if your a newbie because its not fair on the species and this lesson will cost you a ton of money, just get some floridas they are all super hardy!
hope this helps