Could you go Art Deco?
I will try to find some photos for you.

I went to Houzz PHOTOS, scrolled down to "bathrooms," and entered "mauve" in the search box. There are 28 photos there. Maybe one will spark an idea for you. Best wishes.

The other day someone was asking about a green tile in a bathroom. Susan Jablon Mosaic suggested adding a couple colors in a mosaic that incorporated the original color. The mosaic could have trimmed the original tile or been used as an accent in other places in the bathroom. A couple of her color suggestions were really striking. I found a pic with mauve that seemed to do the same thing so thought I'd offer Susan's suggestion along with a photo example.

I found a few photos on the Internet...
First photo combines mauve and tan.
Second photo shows wall hanging.
Third photo shows mauve, tan, and turquoise ornamental tile.
Fourth photo could be a wallpaper design.

One more... This photo suggests a shell theme with possible colors to use with mauve.

To get the best suggestions, a photo of the actual space would help you tremendously.

Alot of houses from the 20's through the 40's combined a color tile with black trim. Strong, and not to everyone's taste, but authentic. Could you mix some blalck with it?

If not, everything here in france these days is mauve and gray. Again - you either like it or hate it, but it seems to work for many.

This is a perfect example as to why big ticket items should always be neutral. I would have a company like Miracle Method come out and spray the tile white. It's cheaper and easier than replacing, and depending on when the tile was mfg'd it could contain lead. You could spend years and $$$ trying to make it work and never be happy, at least that would be me!!!

Here are some pictures of the bath, it looks a bit more pinky in the pictures then mauve. Only place there is no tile is on the common walls...

Oh it's so 40's - looks exactly like the house I grew up in. It is starting to be kind of trendy again - are you sure you can't stand it any longer?

Oh, I love it! It's in fabulous condition and I think you have a lot of possibilities. Normally I"m not a huge fan of wallpaper but a retro print might look amazing with the tile. A warm gray wall color would look great too. I had 1950s pink-and-burgandy in an old bathroom, and once I added a new toilet and pedestal sink, found a great printed shower curtain and towels, and replaced the medicine cabinet with an antique etched-glass beauty (found on eBay!), it looked amazing. Have fun and embrace the retro! :)

I am thinking ... that to contemporize a mauve tile in the bathroom, you could try adding bright silver metallics? Install some awesome lighting fixtures, towel and other accessories. A brushed nickel waste basket and laundry hamper? The Faucets could be over the top and gleaming, even use a metal sink?