Hello Chuck,
Thank you for your informative review on your experience with out Fine Fissured 12 X 12 tiles. Depending on the environment the tiles are in, sun exposure, dust/dirt collection on the tile, etc. the tiles can discolor or yellow over time. The new tiles are all painted with our standard white color which would explain why they don't completely match but is to be expected. If there is anything we can do to assist you further, please don't hesitate to call us at 1-877-276-7876 option 2.