I don't see a problem as long as there aren't height issues. I would think the toilet could be adjusted to the 2 layers of tile. However, I just had tile removed from a bathroom and replaced with a different kind and it wasn't as laborious or dusty a task as I'd expected. It came out pretty easily. But why pay the cost if you don't have to? Sue

I can't help but picture orange with this blue. Or a saturated blue and white. A textured all white curtain would look great as well. In no particular order, here are links to a few colourful patterned ones I found: Peaches - orange pink and green - Urban Outfitters Blue and white - Urban Outfitters Flamingo - Anthropologie Orange Contemporary - Rachael Taylor - Wayfair Medallion - Blue and White - Target Navy & white - Wayfair (might be too dark) Orange and white Ikat - Wayfair Lime? (Doesn't look lime on my screen) - Red Barrel Studio - Wayfair Moroccan Orange - Wayfair I think you can have a lot of fun with your shower curtain. So many colours look good with this blue. The trick might be to match the colour intensity.

I believe the difference in color is too great with the white and brown. Why? 3 reasons 1. The products that are cemented to the building you will not redo anytime soon. Messy , dirty, expensive and just not worth the trouble  2. When you add a product to the building structure. Windows , floors they must last a long time. Durability, wear and tear, and STYLE. All equal a story of when the home was designed.  The look over a period of time 10 years + and the home will become "out of date" Needs a face lift . 3. The homes we admire, the Museums, Churches, Libraries, Opera House have one common thread. At a glance they are timeless. Built in 1940, 1990 etc  The crystal clear item is not seen  For this reason I would not go "trendy". Generally our first choice is the right one. Simple and elegant  How do you change this ad time moves on. Color Bedroom a change of bedspread. Bathroom towels become a dark navy or  deep forest green. Yellow for spring  Paint a wall blue, hang a piece of art  The change is simple and your money well spent for resale  Take a moment to do another board  Remove the brown and replace with a neutral. Try an Odegard runner - There are so many options  Enjoy

Can't speak to whether or not you will get tired of a particular look, however, a more neutral color will always allow for greater flexibility in the future. Zellige tiles look more trendy than classic (unless you are in North Africa!) and I've heard they are hard to keep clean in a bathroom. Use that fantastic green color as wall color paint, find a neutral slip rated floor tile in a shape that you love, use traditional 4x4 tiles that are original to so many 1920s Spanish revival homes.