I think you can easily mix birch in with your maple and oak as long as the colours work together and aren't abutting one another. Birch is a hardwood with a tight grain, not dissimilar to maple once stained. Oak has an open grain and generally the graining is quite pronounced when stained, moreso than the maple or birch will be.

You could consider painting the pine on the steps to limit the colour changes throughout. Pine isn't a great choice for stairs or flooring because it is a softwood and can ding and get gouges much easier than hardwood. Pine generally doesn't take stain well so you'd have a hard time getting it to stain and match any of your other flooring choices.

I would be more concerned about finding colours that work well together and focus less on the wood species. For cohesiveness try to stay with a similar size plank in width.

It will be a finishing nightmare in the future. Use red oak to match the wood specie on the first floor. You can always refinish the first floor to match the color later on.

I get what your saying and it makes sense. I just wish I liked the red oak more. It wouldnt be my 1st choice so its hard to pay the $$ to put more of it in.

Somerset has some relatively light stain colored Red Oak in engineered and solid configurations.

I have 2-1/4" solid Red Birch floor throughout my main floor for 18 years. I had it refinished 2 times. I love the warm tone and beautiful grain patterns. However, it is a softer hardwood and easy to be dented. For your case, 2nd floor bedroom level has less use of course, hardness won't play a major role as on main floor. Amendoim is one harder wood species that I had success recommending people who loved Red Birch and American Cherry, but don't like the softness.

Brazilian Oak Amendoim · More Info

Brazilian Oak Amendoim · More Info

Now I don’t know what to do. The flooring guy said red birch is much softer than red oak too. We had birch in our old house (we installed it ourselves) and I remember likingnit

I'm not trying to save money. I literally DO NOT LIKE the downstairs flooring. My husband picked out the golden oak. To me its too orangy colored. I would prefer a light brown. So I want to find something I actually like for upstairs. I am open to keeping red oak so thats its the same, but I cant find anything prefinished that I like...which is why I was thinking red birch instead. I'd prefer to stay with red oak just for consistency sake. Maybe I will have to put in unfinished instead. But that would really be a pain because I would need to move everything upstairs and I dont have anyplace to move it too. I cant move all the furniture myself in a day or 2. I'd prefer pre-finished just because it will be easier and I wont need to leave the house for days while it dries.

Here is my 2-1/4" site finished Red Birch. There are many, many prefinished Red Oak selections out there. 3-1/4" solid is the narrowest width usually. You will find wood floor gloss level quite low in satin or matte.

I wonder you thought about sanding and refinishing your golden oak if you are not fond of the color.

You're going to have to move your furniture either way. Rent a POD and hire a couple guys to put everything in it. The water based polyurethanes dry quickly, don't smell and don't yellow like the oil based ones do.

Have you looked at white oak? We just had a hallway and powder room done in that, site finished, and it's not very noticeably different from the red/white oak combination the builder used originally.