Thanks for you very good question Scandley,
Very well, I first experienced it in London over 30 years ago. It is not a new idea. Then, I was visiting at my wife's aunts flat, and the tub-shower had one of them, to make it more exciting the bathroom was carpeted. Nothing happened, you just have to open your eyes.
There are of course numerous details in the design process that should be looked at by the professionals involved.

I have a biscuit toilet and can't afford to change the tub. We just had a pure white granite sink and counter installed, but don't know what color of tile on the floor and half walls will work with the biscuit colored tub. All I could come up with was a white tile floor and light gray painted walls? Or white: Or Any ideas?

The toilet and tub are both biscuit.

"God is in the detail" Mies van der Rohe. The only suggestion I can give you is to hire a local interior designer, who should have a good eye and experience, and will help you avoid mistakes.
Good luck.

Thank you