Randomly colors the terrain based on the supplied proportions of red, green, blue, and black. If all four numbers are the same, the terrain will have roughly an equal number of patches of each color. If one color has a higher number than the others, it will appear more often on the resulting terrain.
Red (number): The proportion of red patches that you want.
Green (number): The proportion of green patches that you want.
Blue (number): The proportion of blue patches that you want.
Black (number): The proportion of black patches that you want.