And you can just update the old grout. There is a special spray can for this, filled with paint. It is necessary to click on its tip so that the paint is accumulated. And after that it can be used as an ordinary marker. It is suitable for seams of 4 mm. If the seam is somewhat wider, then just draw a few lines parallel to each other. These markers are released only in white. But you can use suture paints that are of different colors instead.
