Gold has been back for a couple of years but I have a feeling that this year the gold trend will fizzle, and I see nice shiny chrome coming back. It is very glam and gives the sparkle that would go well with your marble. I would suggest changing out the gold to chrome if possible.

Agreed, the gold fixtures are dating the powder room the most.

We would mix some silver tones in to counter the gold, and play on the gray in the marble. Don't be afraid to do so! Is the large plate mirror attached to the wall still in tact? If so, simple slim sconces such as this one would streamline with elegance. We might also suggest reducing the right edge of the mirror to contain the mirror glass within the width of the vanity, leaving wall space over the toilet for art. If you do remove the plate mirror, we would recommend a pendant from the ceiling, centered over the sink and a mirror framed in something exotic, like shell. Have you considered a different tone on the ceiling, such as a soft coral or jade? If you want a wallcovering, a grasscloth-look in a silver tone would be a warming, timeless choice, and there are vinyl look-alikes that would perform better in a bathroom. The marble is so commanding, try to keep the rest of the choices less ornamental so they don’t compete too much.