I would pick the tile colors before the vanity. In your case choosing a taupe first might make finding coordinating tile colors difficult.

DH and I argue terribly when we do a renovation. He can usually get onboard if he sees I am set on a particular choice.

When we did our master bathroom, I knew I wanted gray and white.

I find my bathroom spa like and not boring. If I want a jolt, there are many color combinations I can bring in with the towels, accessories and mats.

My youngest has a subtle marble pore line from The Tile Shop.

here is a pix during reno.

Floor and tub wall should be the same tile for sure. If you both like white with minimal go for it. It’s a pretty and timeless look. Go with matte though , not a shiny / glossy finish.... I would also add a “mat” / like a square of different tile in the middle of the floor. Like right by the opening of the vanity maybe some herringbone. For the shower go with similar floor tile in a different shape .... I loveeee finger tiles. You can even do a white /gray rocky pebbly look for the shower pan