When it comes time to re-do your bathroom, there are a lot of decisions that need to be made. The shower design, showerhead and hardware, the toilet, the vanities, lighting fixtures -- each of these items is important to the look of the final product. You'll likely be so immersed in the decision-making process for the big ticket items that seemingly small matters like grout color may not seem that important. But this particular smaller decision not only affects the aesthetic of the finished product, it can also affect how much work you put into the maintenance of the bathroom once it's finished.
If you're going for a light, bright bathroom, there's a good chance you'll have some kind of white flooring, whether it's alone or with a color. So you'll probably want a lighter grout with the light tile. But you may not think about the fact that light colored grout requires a lot more maintenance over the years. That lovely white grout eventually darkens and if you want to restore it to its former brightness, you'll be required to get intimate with an item called a grout scrubbing tool. It's not all that fun to use, but it's a must-have to keep that light colored grout glowing.