OK...

I have an old 1925 house with original white oak flooring. I recently tore out my kitchen and the fir floors that were a wreck. I found what I thought to be the exact match to my existing flooring (but with a bright poly finish) at our local used building materials warehouse.

I cut out strips of my old flooring, feathered in the new to me flooring and thought all was grand.........Just sanded the floors this weekend and what I thought was color from the thick poly finish was not....It turns out that I feathered red oak flooring into my existing white oak floor.

I think it would have worked OK if i had just terminated the old flooring, provided a transition and then added the new flooring....

Anyone have any suggestions as to staining the floors to come closer to matching? Or should I painstakingly cut the feathers out and replace with white oak and provide the transition strip as stated above?????

any help would be great.

That happened to us once an a huge renovation project. Our estimator mis-read the material on-site and our blind installers did all the repairs with red oak instead of white. There were large areas of feathering in as well as numerous individual board replacements. Well, there is no easy fix, but this is what I came up with:
I mixed a stain that was slightly lighter in tone than what the client wanted but the same colour (if you know what I mean). But before applying that to the floor, I stained a piece of the white oak, and a piece of the red oak, and adjusted a part of this stain to add more brown to the stain that I applied to the red oak sections. Then I used these two stains, the more brown colour to the red oak pieces, the non-adjusted stain to the white oak sections, and when this dried, I applied the original slightly lighter stain over the whole floor.
Sheesh, would you believe this actually worked? And wasn't really all that difficult compared to undoing all the repair work that had been done.
The only thing missing here is the information about the "blind" installer. Some might even think it was me, but I can't remember.

I would stain the floor, this will hide the difference.

as mentioned, staining is the only cure short of ripping out the red and replacing it with white. The issue is that staining the red oak alone wont really do it. Both woods need to be stained and the stain needs to be adjusted for the red oak.

I generally would try to get some red pigment into the white oak and no red pigment into the red oak. The Red oak also needs to be stained darker than the white.

So you could try something like this:

Stain the white oak with a mix of early American perhaps some natural to cut it a little and make it lighter.
Stain the red oak with a mix of provincial and natural

The principal is that white oak is browner and darker than Red oak plus red oak has stronger red tones. So staining both species with the same exact color really wont solve the problem.