I was about to buy some black granite tiles and white grout today, but was suddenly advised to get black grout instead.

I was told the white grout would get dirty too quickly and look crap after a couple of months.

My concern is that the floor will look too black, I am tiling a kitchen approx 17 sqm.

Does anyone have any photos of black granite tiles with black grout?

Go half way and use a grey grout..............us an epoxy grout in white.............if you want normal grout in white then seal it.

I was even told that after sealing a normal grout, people have had experiences of it getting grubbing and discolouring, have you experienced this?

You can do, that is why epoxy is the way to proceed if you want white. Not for the feint hearted though, it isn't an easy job to do.