Hi, I just saw this! Each row has a rectangle over it whose purpose is to tint all the other objects in the row a given color. If you're using Godot, you can use a solid white rectangle, set its Material to a new CanvasItemMaterial with blend mode "Mul" (in any other engine, there may be an equivalent "multiply" blend mode). Then, by changing the rectangle's Modulate color, anything underneath the rectangle is tinted that same color (all the platforms here are actually white; they're just tinted by that rectangle). From there, I had a counter that kept track of how many rows spawned, and for each new row, I would tint it the next color in the sequence.