I think the layout is the problem. The dominant feature is the toilet in the middle of the room. In an ideal world, you'd move the toilet over to the wall opposite the tub, even though it'd cost you some vanity space.

I would prefer a grey-blue, but I think the tone is right; that is, I don't think it's "too blue".

The other issue, which is a whole lot easier to deal with is that it isn't finished yet. You need a real shower curtain -- something pretty with a pattern -- some art work, towels to soften things up, floor mats and vanity hardware. Once this is done, the room will "come together".

try a warmer gray. the one you have leans too blue/purple.

I looked up Memory Lane, and it's very blue. looks different in your bathroom. what temp bulbs are you using?

here are some BM colors so you know what to look for

BM cumulus cloud

I would seriously ditch that shower curtain. it completely detracts from the tub/tile and hides your tile work.

try a partial glass, instead of doors if you like

or do frameless doors.

bring in some art, or try wood shelving (to lend some organic warmth) over the toilet.

This will sound crazy but the blue gray is too close to the grey from the marble tile. It is close in the value (light and dark) but the blue hue is just enough off to notice. So a little deeper blue (or other color) would look like an intentional contrast. However, like Mrs.Pete says, other decor and lighting could make it all come together. So i would try decor for accent color before changing the paint.

Before repainting experiment with different light bulbs. Try a daylight bulb, cool bulb. Warm maybe usually too yellow in bathroom with Grey.

It's amazing how much a bulb hue can change a color.

After getting lightning to your liking, then choose paint colors. Paint 3 of your favorite in shadows and direct light then see them with lights on and off then choose your favorite

If there's nothing in walls maybe a recess cabinet or opening above toilet.

LED lighting a glass shower screen and a gray from the tile in the shower

I am sure you want to stay within budget with your bath remodel. I would suggest getting a curved shower rod and a lovely shower curtain. Mirrors and pictures will help also.