From the Glossy Page Blog

I did not know when installing the tiles we had a choice of colored grouting. I thought it was always white, now I find out that we could go dark if the tile was say navy colored. And we could also go lighter grout colors, with light tiles. But, when he said we could go dark with light, I thought that would look gross. As I saw my neighbors do that and it looked like they had gotten really dirty and wouldn’t come clean in the grouting grooves, but I told them it looked nice, after all they had to live with it not me. I just know that I would not choose dark for light tiles.