Grx.color_build_grayscale

@accepts(guint8, guint8, guint8)
@returns(Grx.Color)
def color_build_grayscale(r, g, b):
    # Python wrapper for grx_color_build_grayscale()

Build a grayscale color value based on the current graphics mode.

This will not allocate a new color even if a color table is being used.