Pretty room! When I looked at the pic, the first thing that came to my mind was cream curtain panels. But since you can't put nails in the walls, blinds are your only option.

I would do natural woven shades. Depending on the level of privacy and light control you desire, you might need a lining as well.

Thanks for this suggestion. One concern I had was whether the color would be too close to the wall color. I know there are lots of patterns to choose from; I just didn’t want it to become too dark.

I would do inside mount roman shades