I would go with a cream or a shade of white. What color is the trim?

Well you can certainly go with lighter color, like maybe off white or ivory or cream..something taken from your granite.

(Don't remember BM whites really, except for Swiss Coffee, and another one that will read as too pink and that's not what you're looking for.)

I'm not sure it'll make other colors go away, anymore than they're already are, nicely blended in now..the current wall color seems pretty perfect. And it's the feeling of blended in that makes colors seem less visible, less standing out. I think...

I do wonder though whether going with the darkest colors from your granite-something like warm brownish black-will be worth to check out, first in a sample of course, and if you're ready for taking a risk like that-because with color on the wall that is dark and deep, (but still works with current finishes), you'll have enough power of that color so it swallows the rest so to say..

It can be very statement, and migh feel like too much, and I don't know what happens with the lighting in your bath. But when you gather samples to try-I'd check out this idea. Just in case it works and you suddenly like it.

Here's a link that may help you. For me, it would be Alabaster and I would paint walls and ceiling so no other white interferes. Alabaster is yummy and would be a perfect blend with your sink top. https://www.kylieminteriors.ca/the-4-best-white-paint-colours-sherwin-williams/