It is Light Brown Emperador marble. Hope this helps and thank you!!

You said the vanity is custom but I have an identical one here, image attached. So is there a manufacturer that makes them or was yours just a duplicate of smth you found on picture and not "custom designed"?

Hi. As far as I'm aware there is not a manufacturer making this vanity. I agree the image you have attached is similar in shape and style to the one in this bath, but all of the details are definitively different including the moldings and the legs. This is not a complicated design really but made to look like a piece of furniture and a concept that designers use in more formal baths that need something elegant and more refined. The vanity you have attached honestly looks as if it has been custom fabricated as well. Good luck with your quest and if you find a manufacturer that does make this let me know!