I don't know if this style would work for you at all, but I'm seeing some really gorgeous bathrooms and kitchens with patterned encaustic ( or faux encaustic) tiles.

Seems like real encaustic tiles have some sealing and upkeep needs - you'd want to read further about it. But there are ceramic tiles made to look like this that would be less upkeep and look just as nice.

Here are a couple that might work with your colours and choices so far:

I can't put my hands on the picture but a few months ago there was a lovely kitchen shown in the forums with encaustic flooring and oh my, it was gorgeous.

Here is a finished washroom with patterned floor. The style might be a bit rustic for your choices, but worth looking at for ideas.

Finished washroom with patterned floor

Artistic Tile has some great porcelain options.

Have you chosen your slab of Taj Mahal for the counter? The sample piece looks quite taupe to me, but I've seen slabs with greens and golds in them. Maybe you should get your full slab if you haven't already and make your flooring choices based on the colours in the counter.

Anyway, here are some thoughts I had for floor tile choices but they maybe won't work depending on the slab of your counter and what the colour variations are. If your husband doesn't like patterns, he may not like some of these:

I thought this one was very pretty. Some colour variation but quite subtle. It has green in it, so if your counter has some green it might work together.

Cultiva Bardiglio Cenere Matte Porcelain Tile | TileBar.com · More Info

These look more blue than green or grey but there are a million choices of penny rounds that might work colourwise for you, if you like that style.

Nirvana Bliss Rimmed 1" Circles Ceramic Tile | TileBar.com · More Info

This one is meant to mimic concrete I think, but I liked the colour and the slight variation around the edges of the tile to give it a bit of interest.

Revel Dark Gray 32x32 Porcelain Tile | TileBar.com · More Info

I like this one very much, but mainly because it is herringbone which is my all time favourite pattern. It is a bit on the dark side, but I see some taupes that might work well with your counter and the darker colours as well makes it look quite sophisticated. The white grout makes it look good and would work well with the white vanity.

Marble Mosaics – Toronto Tiles | Saltillo Imports Inc. Toronto · More Info

This one, I thought the little squares which are pearlescent might look nice with your counters. It is a very classic pattern that I've always liked.

Marble Mosaics – Toronto Tiles | Saltillo Imports Inc. Toronto · More Info

I know these choices are kind of all over the place. I tried to really pull some different ideas out that to me at least, still look classic and formal. I don't know if these ideas match your ideas of formal.

One other thing to consider is slate tiles. There are many colour choices and it looks very nice. I have brushed slate so it is very smooth, no rough edges. I like it very much. I'm suggesting a dark grey or black slate - not the rusty tones that some associate with slate.

Edited to add.....I would definitely think about in floor heating if you choose tile. That is a nice little luxury that I don't think anyone will regret. There is nothing quite like stepping onto cold tiles in bare feet.

Hi. I'm in the same exact position that you were 2 years ago. Love my Taj Mahal quartzite, but can't seem to find a good floor tile. If you get this message will you share what you eventually went with please? Thanks!