Lovely home!

If you can't lower the dining table, you can probably raise the chairs a bit -- talk to a furniture repair place.

Throw some teal pillows on the sofas in the family room to bring in the dining room color. THAT should be your signature color throughout all your rooms. Pull that color in through artwork, rug, or lamps and cookbooks, bowls and whatnot in the kitchen.
Also, you need to center all the family room furniture to the fireplace; pull that sofa away from the wall. And center the rug, too, until you get another one (though I don't hate the rug). I have pale gray walls throughout our open floor plan but add color in the ways I mentioned above. You don't really have much to do as for the most part, it all looks really great.
I don't hate that dining room chair, but it actually doesn't look that comfortable. Is it? If not, keep looking. You'll find something.

You have a beautiful home! I would also suggest centering the sofas with the fireplace (if possible). I also agree with seeing if you can lower the dining table by cutting down the legs

I would start with the room with the fp and find a rug with rust, turqoise and maybe yellow in it. I would also use some art in that space that pulls colors from the rug. That along with some throw pillows with similar colors would look great.

Along that vein I would also consider reupholstering the red chairs in a deep rust color.

Here are a couple of rugs from overstock that might look nice or give you ideas.

I agree with seeing about lowering the table or getting longer legs to make the chairs taller. The table would seem to be the easiest, but if the chairs are really low it might be better to raise them so the table doesn't become too short for new chairs down the road.

I'm not a rust person -- oranges, yellows and yellowy greens just aren't in my indoor palette unless we are talking lemons, limes, etc. So I saw things going in a different direction --- recover the chairs (or replace) with a deeper version of the DR wall accent color -- looks like that would be a gorgeous peacock or deep jewel teal. I'd look a warmer grey for the FR and kitchen if it will work with that backsplash -- something in the accessible beige, agreeable grey, perfect greige category -- they work well with grey and the dark wood/white trim.

I got interrupted by a couple of phone calls -- I don't remember if there was something else right now, but that starts a different direction for you to consider. And I would also adjust the FR layout --- pulling the sofas to center seems like the place to start.

Thanks for all the advice! I do realize that the rug/ coffee table is off-center in the Fr, but when I pull the sofa forward, the space between the back of it and the wall looks weird. I guess no one thought painting the walls a brighter color is a good idea- I was on the fence, but DH was pushing for it. I do love the rust/blue rug that aktillery posted. I know that I need art on the big wall behind the blue sofa, but the painting I bought in Berlin did not look right. I don't like to just run out and purchase art, so I will wait until something speaks to me somewhere else in my travels. That dining chair is the perfect height, but I will keep looking. As for my red chairs, what color should I be looking at if I reupholster?

Maybe you could reupholster them in a mustard yellow or whatever yellow that is in your artwork in the adjacent dining room? They are lovely chairs and the current color is lovely!

I'm wondering if you could put a console table on the wall behind the sofa if you center it on the fireplace. Something kind of modern and shallow that will give you a place to add turquoise accessories, etc.

I love your house (your kitchen is one of my favorites). What do you think of painting your living room a much lighter shade of the same color as in your dining room? Then you could add some pillows in a more saturated and patterned version of the color on the gray sofas. As you said, the art will come in its own sweet time.

I like the suggestions the others posted, so won't offer much more. Your dining room table and chairs look good together, so I agree with the idea to either lower the table or raise the chairs.

Your home is lovely!

Firstly, I'd have to say I love the color/vibe of your home. It feels very clean. I would agree with the people above. I feel you can make the most of the teal/light blue by adding some pillows in that color to complement the room with the dining table.