Is the wall grout grey, or dingy? Either way it will benefit from a scrubbing. Here is a great DIY grout cleaner that I love: https://www.bobvila.com/articles/homemade-grout-cleaner/
Since I'm guessing you don't want to paint the vanity/med cab again I would use a light blue-grey on the walls. To choose a good colour, you could bring home lots of different washcloths in different shades of blue and grey. Hang them on the vanity knobs and see which sings! Buy two complete sets of that one, and return the rest :) Then colour match the towels and lighten it one shade for your walls.
I'd keep the copper art, it is neat and is appropriate for a bathroom. But I would center it over the toilet. Then I would get new copper hardware for the vanity/med cab.
New shower curtain in shades of chocolate and blue or chocolate and cream and you're done!
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teal ocean BM
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