Looks very pretty and a nice neutral background. Paint the walls and vanity the same blue--can you show the vanity and the rest of the room?

I like grayed-down blues, like Ben Moore Van Courtland Blue, Santorini blue, Boothbay gray, Smoke, Water's Edge,

One paint matches the floor and the other is darker than the floor.

BM Lily White

even better with the gray... SW Silent Ripple. Sample in your light.

... you know what they say about opinions.

I would not recommend some so pale as Lily White. Something darker would be a better choice for more contrast. A very pale blue could fight with any blue tones in the tiles.

One of the most popular paint colors for bathrooms is SW Sea Salt. BM Quiet Moments is similar. They are blue-green-grays. They look different in every room depending on the lighting so you will need to sample, but they might be a good starting point for you to decide if you want to move more towards blue or green. I have a gray and white bathroom that I painted a pale green. Everyone doesn't have the same color preference, so you have to please yourself. Northern light is cool, so green will look warmer than blue.

Choose the blue for the vanity first. That will drive the bus for selecting a blue for the walls.