What is the color on the back of the tile?

STONE: Natural stone tile colors permeate through to the bottom of the tile. The surface of the tile will have a polished, matte, or honed finish while the bottom and sides remain unfinished.  

TILE: Porcelain and ceramic are manmade materials, and the color will not always permeate throughout the body of the tile. However, the back color of the tile may vary. Tiles may be a through, standard, color, or double-loaded body. The bottom and sides of porcelain and ceramic tiles will remain unfinished.