Solution: Textures couldn’t be used due to memory and build size limits, so I created a custom shader driven by about 10 float parameters per cell to control appearance. These parameters were the only data stored—saving memory and storage—giving consistent visuals in-game and for rendering. I automated the PNG export with a dedicated Unity build that recreated each cell from parameters, rendered, captured, and uploaded the image, distributed across multiple machines to handle all 5 million variations efficiently.