Wow, I've never seen anything like that floor before. I hope you'll post some more pictures of everything as you complete it. I'd probably choose cream - the color of the tiles - towels and let the other elements be the stars, but some towels/rugs the color of the walls might look nice, too. I think you have enough browns, so I'd stay away from those.

For the window, you could try a cream linen with trim the same color as the walls. Beautiful wall color by the way.

I agree that cream or ivory would work for sure for towels. But you could try chocolate brown just for the drama. I'd probably buy something returnable and bring it home and see how you like it. With the cool sage green on the walls though, it might be too much brown. If you could find a malt brown or greyed brown (which I can almost see in your floor I think), something between cream and chocolate, it could work as a nice compromise.

Thank you for your input. I am nervous with colors and tend to either "over-do" or

get too matchy.

Oh, my goodness - this is going to be gorgeous! I agree with using cream-colored towels. That was my first thought, before I read the other responses.