Row 0 stays all blue. Row 2 stays all green. In row 1, blue takes the center cell (1,1), changing it from red to blue. Then green takes both edge cells (1,0) and (1,2), changing them from red to green. So the masked grid has row 0 as [blue, blue, blue], row 1 as [green, blue, green], row 2 as [green, green, green].