I might be unusual but I probably wouldn’t try to match them. Id do a contrast instead. Maybe go super light or a very different tone on the basement floor. something that harmonizes but is definitely different. Good luck whatever you decide!

The Kid Room 1 looks like the furniture is limited in size duration once the child is past the age of 5 or so. Have you considered a King size bed for the master? If so, you might not be keeping the same furniture there long-term, either. Kid Room 2's headboard could be recovered in a teen-friendly fabric if you wanted for a color change. I think you should just pick a flooring color that is your favorite and deal with the furniture in the future. Rugs and other decor you might have around the house will mask the flooring color anyway to some degree. I'm not a fan of painting furniture. I had a large chest of drawers for decades that was painted and required repainting several times. The finish was never robust at all, and it had to be handled very carefully and still didn't look the greatest.

I'm sorry but the only option (to get what you want) is to sand and refinish ALL of it at once. If you had planned on that in the first place, your flooring professionals would have matched the species and the cut and the grade of floor. They also would have matched the THICKNESS of the planks. Or ideally they would have told you how it was going to turn out...and that the best option = remove the old and lay all the same floor. It is CHEAPER than doing a sand/refinish on Aluminium Oxide floors for the TOTAL square footage. Sigh. I think you have TWO different species of wood. You certainly have two different GRADES of wood (the new one has ++++ plank variation and HEAVY grain presentation. This tells me that if you sand all of this down you will STILL have two floors that look VERY different...even with the same stain. Right now my 'fix' = remove the old wood in the entrance/foyer. Use the entrances to the other rooms as the 'break'. Use the edge of the new wood as the break. Now you drop in stone or porcelain or vinyl that LOOKS like vinyl or porcelain. By removing the SMALL amount of old wood in the entrance you will REMOVE the eye sore that is 'mismatched' wood floors touching one another. It will do the 'most for the least'. Removing the old wood and prepping the subfloor = $2/sf. New stone-look vinyl tiles = $4/sf. Cost of install = $3/sf. Total cost of job = $9/sf. Size of the job? Looks to be about 100sf = $900 and you have a BEAUTIFUL foyer without ANYONE noticing the two woods are not the 'same'. It is the simplest, easiest way to fix this without messing around with sand/refinishing wood that shouldn't be touching one another anyways.

overwhelming votes for trend replacement! ouch... that will cost a pretty penny i think. we were trying to stay within budget and stain to match the flooring. in our old house, we had an even more contrasted situation and i didn't mind it - brazilian cherry flooring and red oak stairs. the stairs were stained to match the "red" tones of the flooring and it didn't look bad. is replacing the treads a massive effort? i'm concerned about the wall trim around the treads... and how many rabbit holes we could go down to change them.