upstairs and main floor do not need to match.

I think a main living floor should be a medium to light for daily living.

Dark floors show more dust as light shines across the flooring.

I just put in a White Birch and LOVE it... reflects the natural light and makes the rooms feel fresh. Do what you like.

I prefer all the wood floors in the house to match, or it can look like you updated at different times and didn't have the money to unify things! This is more of an issue with pre-finished floors that have been discontinued.

I like your upstairs stain color, so I would continue that throughout the house. Lighter stains have been in for a few years, so you are most likely being influenced by that "trend". The upstairs is a nice classic medium brown so you wouldn't be making a "mistake" and you would save money.

Thanks everyone. @chispa would you have concerns about the two-tone wood look with the light cabinet island and darker kitchen floors?

I would hope that when you picked the island cabinet color you used your upstairs wood floors as a starting point? No?

If you didn't even consider the upstairs floor, you could end up with 2 wood stains that aren't the best pairing, but only you can say. Take a door or drawer front off, and look at it with the current wood floors upstairs.

No, my upstairs floors are dark and I wanted a light wood/oak island for the kitchen. I'm not sure if the dark floors and light island clash, or if the woods should match closely (and then I'd need to go with light floors everywhere).

I’d keep the flooring consistent throughout the house. Here are two examples of a light cabinet with dark floors. They look beautiful.

I think the dark wood flooring will go with kitchen and prefer for whole house to match. that being said i prefer lighter floors so had i moved in with dark floors upstairs would be ok with different colors. since you chose dark brown i’m assuming you like them!