More cellular automata stuff. Here's how these patterns are made (warning: boring & messy):

First, each cell gets a random number, 0-99. Then, each cell looks at itself and its 8 neighbors (call this the "area"). If more than 80% of the cells in the area are above 50 the cell becomes 3; if 60-80% of the cells in the area are above 50 the cell becomes 2; if 40-60% of the cells in the area are above 50 the cell becomes 1; if less than 40% of the cells in the area are above 50 the cell becomes 0. Now, each cell looks at itself, its 8 neighbors, and each of

*those*neighbors' 8 neighbors (call this the "region"). If at least 2 cells in the region are 2's or 3's, the cell becomes 1

*unless*the sum of the orthogonally adjacent cells is less than 3 (in which case the cell becomes 0). In all other cases, the cell becomes 0. 1's are yellow, 0's are gray.