# File lib/cairo/color.rb, line 185
      def to_rgb
        one_k = 1.0 - @key_plate
        rgba = [
                (1.0 - @cyan) * one_k,
                (1.0 - @magenta) * one_k,
                (1.0 - @yellow) * one_k,
                @alpha,
               ]
        RGB.new(*rgba)
      end