Hello! We recently installed a marble basketweave tile floor in our powder room. After debating on far too many shades of grey, we decided on Mapei Cobblestone grout and was in love with the way the grout looked wet. As it dried, it lightened and I will say it is accurate to the color on the bag, but as a result the tile has lost a lot of its dimension it had when the grout was wet and had more contrast. It is totally our mistake that we picked a color too light and not a malfunction of the product. However, I'm curious if there is a sealer I can use to help darken the grout back to how it looked when it was wet. I did use an impregnating sealer before grouting the marble. Any suggestions on how we might be able to get that pop back in our grout while still being cautious of the marble? Thanks in advance!

(Photo of grout when wet - vanity will be painted next in progression)