Reference: pmToMonochromatic
pmToMonochromatic(pm, hue) returns the pixmap pm with the hue of all pixels set to the fixed value hue, and the saturation set to 1. The value of each pixel is not affected.
pmToMonochromatic(pm, hue) returns the pixmap pm with the hue of all pixels set to the fixed value hue, and the saturation set to 1. The value of each pixel is not affected.