Wow, what great natural light! Good lighting is so important in a home. While I am unable to see the draperies you are referring to, I would still suggest mounting roman shades on the insides of these window frames. Attached is an image with a similar feel - the roman shades unify the look, giving it a tailored feel, without being too overwhelming or stuffy. The neutral color and relaxed style will play well with your current pieces.

Agree with Loom Decor, roman shades would be great.

Here are the drapes. Don't know why it didn't load before. User error?

If you don't need privacy or light control, leave them bare. The windows are beautiful and it looks like you have a lovely garden view. Don't muck it up with curtains, and for sure NO VALANCE. Roman or top down/bottom up shades, if you must.

Oh, I didn't realize that my original picture was pre-blinds. We do have back neighbors, so yes, privacy is a must.

Are there blinds on the windows now? Are you just wanting a valance or something for function or a visual??

I would take down the drapes, they are draging the whole sunroom vibe. woven blinds, shades only.

Speaking of sunroom, a soft yellow would look nice ;) for the walls

every house I move in, I paint ALL my walls soft yellow---it complements EVERY other color and is so nice in the dreary winters.

From the picture it looks like those windows are not framed in this case I would recommend going with Shutters They can make you frames for the windows and install the shutters flush inside them . I think this would be a great solution for the space.

http://www.blindsdirectcanada.com/shutters-toronto/pvc-polysatin-shutters.html

shutter with frames