My ferals are all colors and the queens vary. I use starter strips only so they can build what they need. If I get the land I want/need I plan on using ferals for queen production, when I learn how. I don't treat and if they don't survive, they don't survive. So far, three years, I have had two hives abscond and two starve with stores they couldn't get to. I picked up three swarms, one of which didn't make it and a cutout that the land owner wants me to get later this summer, when the aster/goldsenrod blooms.
Now that I've bragged about the hives I have :-P to your request. I would definitely look at raising queens from them if they were mine. The little dinky mean black bees that I haven't seen in numbers for years (small swarm two years ago in backyard but they left). If you think it's necessary, you can always breed for a more gentle line. My Russians are normally black and a silver though I do have one that came with a little gold in it and are still that way. If that tree has never been without a hive in the past IMHO 5 years you definitely have survivor stock to work with. I would try hard to keep new blood coming in from other survivor or hygenic stock. That's my opinion, take it for what it's worth. :evil: :lol: