Drapes and a rug with some color would help finish off the space. Maybe a large white art glass bowl on the table.

some drapery panels to flank the windows would soften the space and help with dinner party acoustics. I would also layer an area rug over existing carpet to anchor the table. Colors and styles to your liking.

Love that light! Lovely room.

I agree — a rug with some color/pattern would look great and break up the sea of carpet. (I like your carpet, great texture and backdrop for anything.)

I’d do animal print:

If that doesn’t appeal, you really could do any rug style you like.

Art is wonderful - looks like artist is gifted.. and baby grand too so musically talented as well? Very serene space with no clutter. I would like to see the color blue carried into Dining - a blue & white floral centerpiece on a coordinating table runner? Maybe those glass vases on floor in DR in left far corner with tall blue not floral but grass or reed type filler? Patterned blue jars instead of clear vases on top of corner armoire in LR? My goal would be to add a bit more texture & blue color to rooms. Not sold on adding drapes - I like the clean & uncluttered look you have & my bet is that’s your style & intentional look.

I'd paint the walls a subtle color.

Yes paint the dining room a soft pale blue; this will add color and yet keep the clean, simple look you have already achieved.

Everything is brown and white, which is fine because the art is fabulous. I would bring some of the colors from the living room in, probably on the walls. A soft blue/green would be nice. Love the leopard rug in the mock up! The shutters - I see pretty colors and landscaping out the windows. Do you ever actually close the shutters for privacy? They must be a bitch to dust. I would consider removing them and using panels and sheers, if you need the sheers for privacy.

I would cover the seats in a bright color that picks up those in your painting. The white seats are "expected" with your traditional chairs and table. Go for something unexpected, like maybe a teal or turquoise. Both of those colors would look wonderful with the wood tones you have going on. I also like the idea of a rug but not so much with existing carpet. If the carpet is staying, I'd skip the rug.

Some option to go with some color

or

Thanks for the suggestions. We had the dining room walls painted and we like the white walls better. I’m not a fan of drapes or rugs over the carpet.

I would add a trim rail at the height of your door and paint or wallpaper above the rail to add some color and texture. Adding color to the floor is not going to get the room where you want it.

Below the rail, you could either add some batten strips to make the space more interesting or leave it plain. I had to lower the position of the painting.

This room below has Raffia above the rail and some batten strips added to the wall. Make sure you get the spacing correct. It adds just enough color and texture without being over bearing.

I like njmomma’s idea of orchids. Always a beautiful classic.

Other flowers …

Or hydrangeas …

Or a pretty glass bowl, simple and elegant …

Horchow bowl

Maybe a blue on the ceiling in the DR. I do agree with the others that a rug over the carpet would do the trick, but if you don't want to do that, maybe a more vibrant fabric on the dr seats.