Blue like in the carpet? You don't say the shade of blue, but I would pick a color that is pastel but bright, like aqua or lavender if it looks okay with the rug.

Also a good way to go. An aqua could be OK, but it would have to be just the right one -- more blue than green, maybe a deep cyan. You really could only tell by putting swatches on it in the actual room to make sure it goes. Depends on the wall, depends on the carpet. The right one could be fabulous but the wrong one could be hideous.

Aubergine. (Eggplant.)

Orange or pale yellow!

Blue like in the carpet? You don't say the shade of blue, but I would pick a color that is pastel but bright, like aqua or lavender if it looks okay with the rug.

I'm clueless about decorating - what color/style accent pillows would go with a charcoal sectional sofa? Light brown wood floors, sort of taupe walls, white coffee table and built in cabinets, and a blue/ivory taupe carpet.