If you're in Ohio most likely the floor is pine. I have to do this every day with furniture and finished millwork. First thing you do is get an A/B bleach. One part is lye and the other is a real strong hydrogen peroxide. Mix it half and half as per the directions then cut it in half again with water. Test a drop or two on the new area. You don't want it to turn white but just fade a bit. All you are doing is a quick surface oxidation similar to long term sunlight. If it lightens too much cut it some more. Brush onto the new area but keep it off the old area. Then take canned shellac and cut it 80-90% with denatured alcohol. Test a couple of drops on the new section. With this step you start to pick up your "yellowing" and a bit of color. The main reason though is to give a thin seal coat so any glaze, a stain thinned with naptha or mineral spirits, goes on evenly without any blotching because that's what you have to do next. With the bleaching and shellac you should be making some progress. Now mix a little oil based artist colors with a little japan drier in a 12"x8" (or something like that) shallow tupperware container. Just a couple inch squirt in opposite corners. Start with burnt umber and yellow ochre maybe. Get a short bristle brush about an inch wide, dip it in mineral spirits and pull a little bit of color from your corners and mix in the middle. Keep it thin and transparent. Brush a little on the new area right next to the old floor but only on sealed or finished wood and see what you got. If your gettig there mix a larger amount and coat the are and wipe off what you don't need. If your getting close too a decnt match coat with the thinned shellac again to seal off te progress you've made. Go very quickly with the shellac and don't lap or rebrush or you'll mix with your previous layer and pull it all up. If you're lucky all you'll have to do now is tweek the color a bit. After this you're on your own. Keep in mind that any polyurethane you add later will change the color a bit more. The difference in grain between the old flooring, probably tighter grain, and the new, most likely more flat cut, will further complicate it for you. So paint a bit of graining in if you need to. Add a couple of scratches, a bunch of little ones and a real big one about a foot long for effect. A propane torch with a soldering end on it works great. Drop a cigarette and let it burn a bit and a couple of washed out india ink stains help too. Generally, I approach something like this very confidently, only to find out I need to do something completely different. Good luck and remember, the shellac can be washed off with alcohol and the artists oils will come off with mineral spirits for a while if you need to back out of something. Take it easy on the bleach. Sanding is the only way to back out of that one.