What do you mean bath insert?

I assume you're referring to the tub surround? Honestly, I would go with pure white. Nothing has more longevity than white. As long as it isn't an overly cool white it will be fine with the vanity. Are they going to be next to each other? Are you going to have a shower curtain or glass doors? What color are your floors?

You don't choose a paint color until everything else is in place. There are hundreds of paint colors, so you will find one that works. There is nothing wrong with white walls as you can have towels (and maybe a shower curtain) for color. If you don't want white walls, repost when everything else is done. SW Sea Salt is a popular color for bathrooms as are any number of blues, greens and blue-greens. With a cherry vanity you will have better luck with greens.

I am looking for an accent color for bath towels and the like. Thanks.

since this is a photo, on a monitor, in light that prob isn't your bathroom, choosing a color via this method is hit or miss.

It would be so much better to wait until everything is installed, take better pics and then come back for help.

if you want to take that chip w/you to the paint store and pick out colors you like, bring them back take phtoos and post them here for advice.

BTW, on my monitor that chip has lavender gray tones to it. So if you pick a gray, make sure it's on the lavender side and not the yellow or green end of the spectrum

BM Cement Gray leans lavender. you could try it

soft lilac tones would be pretty w/the vanity stain color

My vanity is the same color as in the above picture.