Bona Classic Seal and Traffic HD in extra matte. It's transitional will work with everything. Nice and simple.

You can't go wrong with a medium brown color that doesn't lean too red ... but nothing is timeless! How timeless something is will be influenced by current trends.

Are you doing site finished or engineered? Narrow, medium or wide planks?

These are my engineered wood floors from Duchateau, Riverstone collection. We have been in the new house 22 months and very happy with the floors so far. Have performed much better than the site finished floors we had in our previous house.

Chispa's suggested a lovely middle-of-the-road color. It's exactly right. Not too light, not too dark, not too much pattern, no gray. This is a flooring that'll match almost any furniture and will stand the test of time.

Either advice is good. If you want light basically a clear water based finish on oak always looks good. If you want some color provincial stain is a design classic.

Water based poly has changed the possibilities from the orange/yellow finishes from the days of oil poly. You have pale brown tones not available in the past. And they are popular using European Oak. Here's some examples-

Lots of sources for these products in 7-12" wide planks. Monarch Plank. Silvan by Flooret. Geowood from Cali. Many others. The width of engineered hardwood is the other step forward. You get more of the structure of the wood.