Draw color patch of specified shape on masked subsystem icon
patch(x, y) patch(x, y, [r g b])
patch(x, y) creates a solid patch having the shape specified by the coordinate vectors x and y. The patch's color is the current foreground color.
patch(x, y, [r g b]) creates a solid patch of the color specified by the vector [r g b], where r is the red component, g the green, and b the blue. For example,
patch([0 .5 1], [0 1 0], [1 0 0])
creates a red triangle on the mask's icon.