Are you using background tiles? How do you have so much colour variation in the blocks?
That is exactly right. The game tiles are stored in an array and written to the background layer. The only sprite is the cursor, which can move or remove game tiles from that array. And I am using the maximum amount of allowable color palettes for the system. I had to get a little creative, so some things share the same palette, like the green game tiles and the main character portrait.