code: function fullHex(hex) {
    return hex.length == 4 ?
      [ '#',
        hex.substring(1, 2), hex.substring(1, 2)
      , hex.substring(2, 3), hex.substring(2, 3)
      , hex.substring(3, 4), hex.substring(3, 4)
      ].join('') : hex
  }
docs: Ensure to six-based hex