I think you have the makings of a very nice bathroom there. I'd leave it as it is and add coloured towels first. I think any of these colours would look great: turquoise, sky blue, green, lemon - the list goes on. Then I would add some greenery such as a potplant or fern. Some candles should finish it nicely. Then stand back to reassess and decide on window covering. Voila!

depending on the size of the existing vanity it should be possible to have a similar new vanity or a custom unit made to replace the original but a chat with a plumber should be arranged to recommend suitable options and plan a schedule to remove the old and install the new, including any necessary waterproofing or tile repairs..btw careful removal could allow the original sink, taps and even the counter to be saved and recycled into a new vanity that matches the bathroom perfectly with the added option of being able to add different doors or drawers to the cabinet

Check the colour wheel for which cream e.g. yellowed pink based and go opposite colour,

Did you both use it in any other parts of your house out of interest? That's what we're looking at doing, daughter's bedroom is first. We've put the three selections on her wall in the quarter, half and full strength. She hasn't chosen which one she wants yet, but has always said she wants grey so guessing she'll go for the full strength. Hubby and I are liking mid strength at this stage which we'll use for the rest of the house I think.