I agree. I think that would look lovely.
What about a pale blue?

I know this isn’t the whole wall. But this photo is inspiring.
The color is similar to BM ocean city blue. I think it could work beautifully just on built ins. Or on the whole wall.

I think the built-ins as installed are already White, so the question is, should the whole room be white to match the built-ins. Sure, why not?

Yes, @palimpsest, thinking of doing everything white

Contractor said he could match walls to the cabinets, but this is how it turned out.  Cabinets definitely not the same color.  What would you do now?

I think this still works because the tile around the firebox does not read as white either and the cabinets tie in with that.

I see the difference and at this point I think it comes down to your preference. Some will appreciate the slight contrast and some will prefer to match it more closely.