Magic method that allows instances of ColorFilter to be called as functions. The filter itself should be called as a function, rather than calling this method directly.
Makes the color darker by the percentage specified in the first argument, or by 10% if no percentage is specified. Percentages should be specified as a float, e.g. an argument of 0.25 will result in a color 25% darker than the original. The darkening conversion is performed by adjusting the y component of the color in XYZ color space.
Makes the color lighter by the percentage specified in the first argument, or by 10% if no percentage is specified. Percentages should be specified as a float, e.g. an argument of 0.25 will result in a color 25% lighter than the original. The lightening conversion is performed by adjusting the y component of the color in XYZ color space.