What color does the gray sofa, white coffee table and TV cabinet give to the TV background wall?

There are a lot of options for this. Your kind of decoration scheme is relatively modern. It's hard to say what you don't see here.,,It's also fooling you to say it.。。 >>>More

I use a bright color to achieve contrast, and I use light blue or light green to harmonize it.

There are too many dark tones, so it's a little lighter, and it's comfortable to look at.

You can choose a black and white wallpaper with a sense of stripes, or you can choose some floral flowers with a sense of beating, the color is not too bright, it is better to be dark, or you can choose, spray paint the wall, and find someone to design the pattern you want.

Yes, it is quite a match, you can match light gray or white curtains, you don't necessarily have to buy solid colors, you can buy ones with patterns or textures.