[header] How to avoid common glass tile installation mistakes [title] Ensure color consistency behind glass tile. [substeps] Since glass can be the sole material in an installation, it is essential to choose a bonding mortar that meets its unique demands. In most cases, the color of the thin-set mortar was not an issue when installing opaque ceramic tile. 
But with clear and translucent glass, the mortar appears through the tile: if the color varies in the mortar, it will in the glass tile too. To eliminate variations across a glass tile installation, choose a glass tile mortar with a bright white shade that is controlled to a consistent standard color.