def +(color2)
    Color.new(
      (self.red + color2.red) / 2.0,
      (self.green + color2.green) / 2.0,
      (self.blue + color2.blue) / 2.0
    )
  end
def +(color2)
    Color.new(
      (self.red + color2.red) / 2.0,
      (self.green + color2.green) / 2.0,
      (self.blue + color2.blue) / 2.0
    )
  end
Compares this Color with another to see which is brighter.
The sum of all components (red + green + blue) for each color determines which is greater.
Averages each component of this Color with the corresponding component of color2, returning a new Color.