Consider solid surfaces such as Corian instead of tile. For the flooring, use patterned sheet vinyl to avoid grout entirely. There are many new patterns available that look like fancy encaustic tile.

In the meantime: 1941 tiles may look good but have a worn surface and grout that is rough from cleaning for 80 years. You can get it professionally cleaned and sealed to give you an easier to clean surface. Using liquid body wash can avoid the reaction that produces soap scum when bar soap reacts with minerals in hard water. Use a squeegee after each shower. A daily shower spray such as "Clean Shower" or the standard recipe on the internet can also cut down on cleaning effort.

If you want a style that looks like you know what you're doing you won't HGTV the bathroom but keep the tile and work with it. People pay a premium to find houses with original tilework.

If the floor in the pictures is what you are thinking about adding why not get bold and use a dark tile on the surround.

There's no way I'm keeping this tile, though. It's four different colors: two yellows and two blues, and I think they added the second yellow AFTER the bath was done. I truly hate it. Normally I'm big on keeping things vintage, which is why it hasn't been changed until now. But it is certainly time, and I think I can get something that looks like someone knew what they were doing without having 1941 yellow tile in my bathroom.

In my experience, most people don't really pay for "vintage" bathrooms like this. It's a very small segment of the population who likes this type of colored bath, and it didn't garner me a premium at my last house with 1951 tile either.

The difference in cleaning effort between 80 year old tile and new tile is astounding. It will be much easier to keep clean. Many ugly tiles were installed beautifully decades ago which is why they weren't removed. The easily removed ugly ones are long gone. When it's time to replace them, it's time.

I think I need to see your bathroom but I will say if you are removing all the tile you might as well spring for a new tub since there are always surprises when removing old tile and nice new soaking tub will be a huge improvemet over an old tub with all nice new tile . I would keep it a bit simpler I like the clean look of 12 x24 porcelain tile on the bathroom floor and the tub wals then add that pattern on the backsplash maybe . You will have tha nice clean look and easy to keep looking nice. BTW I for sure would do a glass shower screen and just use a squeegee after every shower and once a week a good clean. I live where we have hard water and that works for us.

Personally I love the first floor tile you posted! With the right grout the cleaning isnt very hard, most people only have experience with normal old grout, the new stuff generally doesnt stain and doesnt need sealing.