are they real cement tiles or porcelain?

if cement, seal them first before grouting. if doing a dark color, pipe in the grout carefully and don't smear it all over the tiles. do a few tiles at a time, and quickly wipe off excess. (I can't stress enough to seal them very well before grouting)

if they're porcelain or ceramic, they're fine to do a dark color and grout like any other tile.

I did a black w/mine (they are cement. i had to be very careful and not let the black grout get on the white portion. yes I sealed them 4 times prior to grouting!

White on a bathroom floor will get dirty a lot quicker.

the other option is to do a medium gray. gray visually disappears. pick a neutral gray, neither blue or beige.

this is Custom Polyblend.

look at Natural Gray, Platinum, Charcoal or bright white. (just know that the white will get dingy w/use)

Mapei colors. Charcoal, Black, Pearl gray, Silver or White. I used this grout w/mine

Thank you so much! They are porcelain. I’m going to look at those grey grout shades :)

Grey would be my go to..

Yeah...grey.

I did Mapei Charcoal. It looks perfect!

Kate are you able to post pictures of your finished product with the charcoal

Tonya, while waiting for her pics, the charcoal or the black (they are both so close) will look just like this w/your tiles

With the black vanity youre doing, it will look great. I retract my statement that gray is ok! after seeing pics of the gray, I like the darker one, or the white, a lot better