simple color value object

color.rb

class Color < Struct.new(:r, :g, :b)
  def self.hex(value)
    new(*value.to_s.delete('#').scan(/../).map(&:hex))
  end
    
  def hex
    "%.2X%.2X%.2X" % values
  end
  
  def to_s
    hex
  end
  
  def to_ary
    values
  end
  
  def inverse
    self.class.new(*values.map { |v| v ^ 255 })
  end
  
  {
    black:   [0,0,0],
    white:   [255,255,255],
    red:     [255,0,0],
    yellow:  [255,255,0],
    green:   [0,255,0],
    cyan:    [0,255,255],
    blue:    [0,0,255],
    magenta: [255,0,255]
  }.each do |color, values|
    define_singleton_method(color) { new(*values) }
  end
end