Depending on the color of grout used the look of carrara pietra porcelain tile can vary once installed.
Marble backsplash dark grout.
My vote is white it will keep the marble looking pristine and will darken a bit over time matching the look of natural carrara quite well.
Here is carerra marble with medium grey grout.
I hear it quite often dark grout can sometimes seep into the sides of a light marble and stain it causing it to look dingy overall.
That hampton carrara marble backsplash done zo chris loves julia need advice on grout color with carrara marble gray and white marble kitchen reveal maison de pax grout color for white carrera marble tile in shower remodeling 101 how to choose the right tile grout remodelista grout color for white carrera marble tile in shower.
Same 1x3 marble tile diffe grout color wow what a difference floorwhite or light gray grout for carrera marble tile floorgrout color with carrara bianco marble bathroomgrout color with carrara bianco.
I absolutely love it but keep in mind this is 3x6 tile so the grout will be more prominent with tiny tiles simply because there s more grout.
Definitely stay with a lighter color for marble.
Carrara marble shower and vanity gray walls dark gray ceramic tile floor.
Gray grout will emphasize the dramatic gray veins that mimic real carrara marble while the white grout will the porcelain floors light bright and elegant.