Hey everyone, I hired a contractor to do minor renovation for my new home. I wanted a concrete table top with homogeneous tiles for my kitchen. I told my contractor to skim the tile edges to make it into radius (fillet type). Below is the picture of tiles after edge got skimmed. As you can see the there is major color difference between the original surface and skimmed surface. Skimmed surface looking rough faded. Anyone know why? It supposed to be a homogeneous tile. Please advice.