Wouldn't that depend your selections since neither Zellige tiles nor marble come in only one "shade" so to speak.

I have a marble bathroom counter and marble basket weave tile floors. I have hand fired tiles in a deep contrasting color on the walls.

However the marble on my counter is French Vanilla so it is not one of the stereotypical very veined marbles. The basket weave tiles are Calacatta but the basketweave design is more prominent than the Calacatta element in terms of the visual statement.

Go for it! Found these indoor pics.

My bathroom isn’t quite complete yet — we will install shower glass, all the shower hardware, and more period appropriate light switch (I live in a 30s Tudor cottage). But this is calacatta marble with cle weathered white — I think it is so so beautiful together. I can post again when it’s complete!

@Laura - what did you end up doing for your bathroom? I’m going through the same dilemma and need to make a decision for install this week!