docs: function hex2rgb(hex) {
      //validate hex string
      hex = String(hex).replace(/[^0-9a-f]/gi, '')
      // If 3 digit hex color
      if (hex.length < 6) {
        hex = hex[0]+hex[0]+hex[1]+hex[1]+hex[2]+hex[2]
      }
      var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
      return result ? [
        parseInt(result[1], 16)
      , parseInt(result[2], 16)
      , parseInt(result[3], 16)
      ] : null;
    }