You can easily edit both the color of the mosaic itself and the color of the grout. Materials are set to the physical size of 100x100 cm (you need to use UVW modifiers to set the tile size) High resolution textures: 8192 x 8192 pixels.
All the necessary files are in the archive (.ZIP). The archive includes: a folder containing a .mat file and textures (.jpg), as well as YouTube link with a tutorial on how to install and use this materials package.