Grout is the material that fills in the gaps between tiles. It’s most commonly white, though it can be other colors depending on the scheme you want to go for. You can even custom-mix your own grout colors if you can’t find the one you want to perfectly match your vision.

Like any part of the home, grout can get dirty. That once white material will look dull and take on other, undesirable colors. If it’s in the kitchen, this can be partly caused by the grease from cooking. If it’s the bathroom, the culprit can often be soap scum and other grime.

No matter the cause, the grout will need cleaning. But sometimes, the dirt is really packed in.

When cleaning isn’t enough, the usual cure is grinding it out and regrouting. But here’s an easier approach: DAP Kwik Seal Grout Recolor Kit, available at home centers or online. It lets you whiten grimy grout by putting a fresh coating over it in a few hours.

It’s a four-step process. First, you clean and prep the grout with DAP Pre-Treat. Next, apply the Color+Seal coating. Remove the excess, then buff off the haze. The kit contains everything you need and covers about 100 sq. ft. of 4-in. tile. Smaller tile will have more grout lines and require more material.