Truchet tiles, squares diagonally divided into two colored triangles, belong to a class of tiles that inspire pattern design of surprising variability and complexity through their placement on a regular grid. Gradient structures across mosaics are constructed here using generalized Truchet tiles with motifs that align at tile boundaries, and are applied to graphic design and textiles. In one method, tile color motifs systematically evolve in shape across the mosaic, and a second method involves judicious selection of tile brightness from within defined tile families.