Depends on the style/design of your house. Traditional- stain to match floors. Contemporary- go dark/black. I would stain either way as paint will likely not wear as well.

I would match the floor or a tad darker. Don't follow trends - no one can afford to keep up with them, and your home should be what you like:)

I would stain it the darker vein color that runs through your floors. You can take a floor piece to your local paint store or SW & they can match. Just make sure to tell them what type of wood that your railing is made out of.

go dark. personally, I would paint them glossy black. ditto for the treads. Black and white looks great w/your color floors. Or you could try an ebony/black gel stain (General finishes makes a good black gel stain)

or you could do the risers in black and treads to match your flooring

if you want to match the floors, it would look like this