White Floor Tiles - Which colour grout ?

Totally aesthetic choice with a little practicality - light grouts will discolour quickly on floors. The old joke is that grout will always be grey - just if you put it in white it takes a bit longer! No reason not to use a matching grout or a slight contrasting one (generally thought better to use a slightly darker colour) so long as you are aware that it might start to look 'dirty' fairly quickly. Since scraping out grout and re-doing is pretty easy job anyway you could do that in a couple of years if it was getting too discoloured - or use a darker colour to start with.

If you do want to use white grout and want it to stay white, either use a high quality grout and then grout sealer applied a few times. Or you could use a epoxy based grout, they are totally resistant to everything including chemicals and should not discolour but are hard to apply and may not be practical for a large area.

White grout then Dunlop Grout Sealer

I did it grey, looks ok. I reckon the antique white wouldve looked better(at the start) But Its done now so bugger it