I think an emerald green would look great with the brass and sink and touch both the retro and Moroccan themes.

I love the selections so far. I think black walls with a colorful rug would make your fixtures pop, but could also picture this in a very deep dark plum

. In this pic I like that they mixed metals and the mirror was not brass.

Dark plum could be really pretty. Try some samples.

More important than the color is adding a strong Moroccan influence to tie in the wood, sink and brass and also work with the flooring. I’d wallpaper the wall with the sink and only then determine the paint color. I think this paper would work really well with your choices.

https://www.zazzle.com/bohemian_moroccan_wallpaper-256265281186043873?epik=dj0yJnU9QW5lTjQxb3VjaUZkdnFTa1FDSGRUNmZ3UFhESEVPYlImcD0wJm49U3otNkxtc0tKeE83ZDNscmx6eWxyQSZ0PUFBQUFBR2pCaHBB

Yes, there are so many great deep rich plum colors, KILZ® Beet Root, purple is fabulous.

How about this cool Moroccan light fixture to throw a great pattern on to the ceiling and walls, rather than wallpaper.

https://www.amazon.com/Moroccan-Farmhouse-interior-maximalist-Chandelier/dp/B0D75Z9KW7?ref_=pinterest_fplfs&th=1