I like your black vanity but it's the bathtub surround that I find distracting. I would opt for a simple white tile that matches the white of your bathtub. Paint the walls a warm white, find a small washable runner that coordinates with the colour scheme and a nice print for your wall.

I'd also replace the mirror with a narrow black frame and a new sconce above.

The vanity looks to be in nice condition. If you decide to keep it, consider changing mirror and lighting to something lighter. You can bring a touch of black back by using a simple shower curtain. Here’s a couple ideas.