When it comes to choosing the color of the grout, you've got several options to choose from. You could go for a dark or light shade. A dark grout is ideal for a traditional or retro look, while a light one would suit a modern bathroom. Whatever you choose, be sure to choose a color that will complement your tiles.
Gray is another option. This shade of gray will help you make the tile the main feature of the room rather than the grout itself. It works well with white tile and will help to emphasize its pattern. Another good option is a soft gray grout, which will bring out the pattern of the tiles without taking the focus off the tiles.
Dark gray is a popular choice for bathroom tiling. It adds contrast to the white subway tiles and is easier to clean. However, it should not be used with white gloss tiles.