Pretty room. I agree changing the curtains would be on my list too. Their color is dominant in the room & pulls the eye right to them. My thought is to match the wall color - actually a shade or two lighter than wall. That grey color is in the rug too so I think it will tie in nicely. The lighter color of curtain will open up the window wall & I think the effect will be lighter & brighter.

something light, a slub or linen for texture.

a pattern even, at least as light as your rug.

You could pick up the color in the area rug.

Did you paint the frames on the windows to make them stand out? IMO they would look better if less emphasis was focused on the frame and more on the view outside the frame.

A more wood table between the two chairs would anchor the seating area better IMO.

I usually pick a color from the rug so maybe even a bit blue if thta is my monitor saying there is blue in the rug. I really nice pale blue faux silk or a pale blue linen would work well

Love the look of the blue.
Or you can do white.
Lovely space

Maybe the color of the chairs, off-white.

I would go with lighter version of wall, your chairs or rug colors.

or

I would go with something the same color as the wall so the eye will be drawn right out the windows to that nice view. Also, could you swap the table between the white chairs for the one next to the sofa?