Following an Architectural Tiles tutorial I generated a few variations for a circular metallic tile and a multi colored mosaic tile using Substance Designer. A few attributes were exposed in each shader - the grout color in the circular mettalic tiles and the colors of the tiles itself in the mosaic tile example. The shaders were imported in Unity 3D this time and tested in varying light conditions.
Circular Mettalic Tile :
Square Mosaic Tile :