class Sass::Script::Color

def piecewise(other, operation)
  other_num = other.is_a? Number
  other_val = other.value
  if other_num && !other.unitless?
    raise Sass::SyntaxError.new("Cannot add a number with units (#{other}) to a color (#{self}).") 
  end
  rgb = []
  for i in (0...3)
    res = @value[i].send(operation, other_num ? other_val : other_val[i])
    rgb[i] = [ [res, 255].min, 0 ].max
  end
  Color.new(rgb)
end