I think you should just leave them be. Knotty pine is just what you see and it would not look good darker in my opinion. Get used to them.

I live in a hundered year old Victorian house with knotty pine floors and I'm going to tear out the carpet and refinish the floors. I want the floors in my bedroom to be darker though as I'm not a fan of light floors. I don't mind the look of the floors the way they are though. Should I stain the floors or just leave them be? Also, if I choose to stain the floors which darker stains would look best with on a knotty pine floor