Dark grout - some people love it and some people hate it. I happen to be on the loving side of things and there are many reasons why I take this position. Besides being a classic look that allows your beautiful tiles to pop visually, dark grout hides my absolute worst pet peeve - and that is dark grout. Allow me to explain after the jump.
Grout is a necessary evil in the tile world. Ceramic doesn't have enough flexibility to change with the natural shifts a floor makes and remain water tight, so grout fills in the gaps, quite literally. I personally hate seeing large swathes of grout cut into a sparkling tile floor. To me, your standard beige or white grout lines look like old food stuck between pearly white teeth; they just don't have any aesthetic value. The worst is when grout is chosen to match tile perfectly, because the areas which receive the most wear always show darkened lines that stand out to the eye. The resulting effect is of a dirty surface.
So if we need to use grout to make our tiles work, why not make it attractive? When choosing a contrasting grout color, you're making a statement rather than trying to hide it. And when the lines inevitably stain, those marks aren't visible.
Which side of the dark grout debate are you on?