code: protected function colorHexToRGB($color)
      {
          if (!$this->checkColorHex($color)) {
              throw new \InvalidArgumentException('Invalid hexadecimal value ' . $color);
          }
  
          $color = mb_strtolower($color);
          $color = ltrim($color, '#');
          if (mb_strlen($color) === static::HEXADECIMAL_ALIAS_LENGTH) {
              $color = $color[0] . $color[0] . $color[1] . $color[1] . $color[2] . $color[2];
          }
          $color = hexdec($color);
  
          return [
              0xFF & ($color >> 0x10), // Red
              0xFF & ($color >> 0x8), // Green
              0xFF & $color, // Blue
          ];
      }
docs: @param string $color (hexadecimal)
  @exceptions \InvalidArgumentException
  
  @return array (r,g,b)