lighter :: Double -> Color -> Color
lighter d c =
  sameAlpha c $ HSL (hue c) (saturation c) (fence (luminosity c + d))
lighter :: Double -> Color -> Color
lighter d c =
  sameAlpha c $ HSL (hue c) (saturation c) (fence (luminosity c + d))
lighter d c =
  sameAlpha c $ HSL (hue c) (saturation c) (fence (luminosity c + d))