I like white

I was thinking Navy blue but don't know if you want to go that dark. I would change out the rug under your white chairs and get a coordinating one for the new sofa

What's wrong with color? Me, I'd pick a red sofa. There's a limit to how much white/gray/bland you can use before the whole room disappears! Do you know how stunning a sofa in color would be? Doesn't have to be red. Cobalt blue. chrome yellow -- avoid purple. Primary colors work best, but orange is good (my mother had a burnt orange velvet sofa in a gray/white/black living room - it was stunning!) The entire world has painted their houses "50 shades of gray"! (There's not one smidge of gray inside my house. The outside is gray - "Elephant Skin" and "Amazon Stone" -- love the names they give paints. Wonder what it indicates psychologically about what paint names people choose to use. Someone should do a study.) The house is adventurously modern. Be bold.

THEN find a rug.

I think it depends on how adventurous you are I would go the pale blue if you are a bit timid but red with a few red accents in the other spaces would be my choice too. FYI the rug under the table is too small and you will need a afbulous rug in the LR to ground the space guess you can tell which sofa for which rug IMO you need a much more amazing chandalier above the table that one does nothing for the room

I wouldn't go with a pale linen unless you choose slipcovers for easy maintenance. I really do like the look of off-white and adding the color via art and area rugs and cushions. When I see an amazing royal blue sofa in a room here, I really do ADORE IT (my parents had blue velvet) but I like to swap out my colors more frequently than I like to buy new sofas; I've had my slipcovered one for 12 years.

Restoration Hardware has added more leather colors, if you like that, too

I would do either off white for the sofa (if that is practical with your lifestyle) or choose you absolute favorite color and go with that for the sofa and coordinate your accessories/rug. Sometimes it is easier to find the rug first. Say your favorite color is green, find a rug with several colors in it that you like as long as there is that green in it... then green sofa, pull another color from the rug for accents. Add some neutral fabrics or accessories and big floor plants or trees. BIG artwork, nothing dinky..you have a lot of space there.