We have medium to dark gray tiles in the bathroom and I wouldn’t do it again. You can see stains and dirt quite clearly (water spots, toothpaste, etc. – we have children) and the color looks rather cold. We are installing (having installed) wood-look tiles on the ground floor in a medium wood tone, very appealing, somewhat busy as wood usually is, and they were even mistaken for wood when unloading as neighbors came to see what we were getting. Absolutely timeless. I wouldn’t take gray at all anymore. And if it has to be gray, then preferably all uniform.