The first image below has very dark grout and a larger grout line. Keep the traffic in the area in mind when making your choice. How To Choose A Grout Color Grout Color Grout Mosaic Diy Although it may sound strange, grout stains that are close in color to dirt are typically the most successful, because you won’t have to worry about the grout becoming discolored again over. Change grout color from dark to light . Keep in mind that with existing grout, you can change the color only to a darker color; What type of grout can be stain / sealed? Changing existing grout color with a colorant most homeowners would like to avoid removing grout if at all possible. Medically reviewed by dr samantha miller, mbchb. Though it’s not wise to try to lighten this grout with bleach, you do have two other methods you can use to change the color of your grout. Apply diluted bleach and scrub the grout with a rough bristle brush. However, when you use light grout with a darker tile or ...