I would do a sold gray velvet on the chairs seat and use this gorgeous fabric for drapes in the space!....very Country Chic!!

Thanks so much for your input. Gray velvet would be very pretty in a formal space. The style of my furniture is more casual. Do you think the velvet would look right in a more casual setting? The dining set and china cabinet is from the early 90's with a definite country vibe. Painting them helped to bring them up to date but the style is still casual. What do you think...velvet or something else?
(I plan to paint the walls once I've selected a fabric for the chairs.)

I would consider a buffalo check in one of your colors, maybe the black.

This decor reminds me yours. I like fabric pattern and color on your curtains.

No to velvet after a while it will look flat shiny and worn , go for a toile instead and paint or remove the strip of wood from the wall it makes the room look chopped up and smaller.I love your rug and the colours to you have chosen , if you like country then no velvet .

This pic for an inspiration with seats color. Take the solid darkest color from your curtain.

I agree a solid gray will be a great choice. I think I like it better than a pattern on the seats.

Here are your colors from curtain. You can work with them or get complimentary colors or combinations of two.

I would go solid on the chairs, too, so you have the option to switch things up if you want a change with other accessories. If you have the energy and budget, I echo the idea to repaint the room. The green tones aren't doing anything for your furniture or curtains.

Do a gray faux velvet no need to do the real thing!..... like I said it will look Country Chic...you could also do a linen in gray...but would keep the seats solid. Great job it looks wonderful! Love the drape fabric!!
Love this gray and white space with a Chrystal/glass chandelier...

Bette, I adore buffalo checks! I love this suggestion and had not considered this pattern until you mentioned it. It would provide a mix of patterns that appeals to me. It looks so pretty in all the photos you so kindly posted. I'm now on a mission to find the fabric.
celerygirl, thanks so much for all your suggestions and going to the trouble of finding photos to provide inspiration. Thanks especially for showing the colors that coordinate with my curtains. It helped me narrow down my color choice to either the "goldish" brown you showed or to a black buffalo check.
Genevieve, I like your idea to use a toile, but I think I prefer the buffalo check more. Both would give the room a French country look which I hadn't considered but really like. You got me thinking about removing the chair rail. Maybe I'll replace it with wainscoting.
Kailean, I completely agree with you about re painting the room. Seeing the walls in the photo and how awful the colors look with the curtains and china cabinet convinced me I need to change the wall color. Thanks.