Wall color id easy to change . IMO use the same wood as the floors to make life easy.

Hi Patricia, thank you! Do you have any suggestions on wall color direction?

Are you leaving the wood natural? Or are you going to paint it? Type of wood wouldn't matter as much if you are going to paint it. Color of walls depends on the look you're going for.

Hi. Leaving the wood natural for the bookshelves.
The floors are Mueller Graff European Oak “Cote” color.

Will the wood be the color of the piece that is standing up? Or is that just random (part of how construction goes)?

Your room looks like it might be on the dark side so I would lighten the paint colour a lot. But build your bookshelves first. Will be a lot easier to find a paint colour that will complement all elements of your room once the bookshelves are done. For your bookshelves, keep those a light colour as well so they will brighten your room. If you have trouble finding a wood or stain to exactly match your floors, choose a colour or stain that is very different. If you try to match the wood colours and you're slightly off, it will look like a mistake. If you go with a much lighter wood, like the colour of the wood standing against the wall in your second photo, then there will be enough contrast and the 2 colours will go with each other.

Just some wood samples trying to find something that works.

Here are some additional photos. The room is dark today as we have rain, however, it is south/southwest-facing so normally is very bright most of the day.

And one more with a couple wood options

Does anyone have any more thoughts after seeing these wood pieces?

The darker sample on the left looks good. Next, pick your furniture and area rug (if using one). Paint color comes last.

Thank you

I would choose my wood based on price, availability, and ease of finishing. When I did built in bookcases, I used birch plywood. Maple is one of my favorite woods but difficult to stain evenly so best used in a natural finish. Pine is cheap and easy to get but even harder to get a nice looking finish job than maple. Walnut is pretty but pricey. Oak is a classic but many people don't like the open grain. One tip...if you are doing adjustable shelving, consider buying the uprights predrilled or buy a piece of pegboard to use as a drilling jig for the peg holes.

Any of those materials will look nice if built with good design, quality workmanship and good finishing.