“Without contrast to set apart the grout from the tile, it has a strange ... if the sealant is of a higher quality than the paint, it may seal in the exothermic reaction of the paint below ...

Zep Grout Cleaner and Brightener Zep Grout Cleaner and Brightener $8.79 at Amazon Grout Pen White Tile Paint Marker Grout ... involves regularly cleaning and sealing grout with a grout sealer ...