Don’t despair if your bathroom tile sports dingy grout lines. With this grout makeover tutorial, you have the ability to skip the need to retile an entire space—which can quickly get messy and costly—and instead use a grout paint pen to make the space look bright white again. Prepare a vacuum and mop, 2–3 grout paint pens, depending on the square footage of tile, scrap cardboard, a cup of clean tap water, a clean, dry rag. Prep the tiled work area by carefully vacuuming up any dust or hair, and then mopping with a mild floor cleaning solution. Be sure to clean the grout lines in particular in this step so that it will take the paint properly. Keep reading what to do in the source.