I have ceramic tile with white grout on my kitchen floor. The grout hasn’t been sealed and has gotten quite dirty. Is there a way to darken grout before sealing it?
Try cleaning it first, then darkening, then sealing. Several commercial cleaning products will take out most rust and mineral deposit stains. Check at a tile store and follow the instructions for the product carefully. Several products, also available at tile stores, can add darkening or coloring agents to grout and will seal it against future staining.