How do I pick a wall color to match these tiles?

This is another picture showing how much lifht comes in the room thanks again

You don't match color to a floor, you consider the floor. Always start with patterns and colors you'll use in room. Pattern is best it gives you choices.

It looks like your tiles are in the warm category. You can go for a soft beige in this color scale as well and the walls and the floor would be very calming. if you're looking for a little more contrast, something that makes the floor pop, a light color on the cool side of the wheel (like a very light blue/gray) would bring out the floor.

That looks so neutral, you could use any color you like. What are you wanting to paint?

Go to the paint store and get a bunch of color cards that you like and think will go with the floor and everything else you're putting in the room and pick a few out of the box ones too (you never know). Using painters tape, tape them on the walls of the room you want to paint. Go into the room at different times of day and in different kinds of weather. Throw them away as you eliminate them. When you have a few, take them to the paint store and get sample pints and paint them on the walls. Do the same thing you did with the color cards until you have the one you want.

A soft gray for the walls to pick up the marble flooring. If you are not in love with the floor, paint it to something you like.