在PHP 中，如果獲取的顏色代碼是16 進制的格式，怎麼轉成RGB 數組格式呢？

function wpjam_hex2rgb($hex) {
   $hex = str_replace("#", "", $hex);

   if(strlen($hex) == 3) {
      $r = hexdec(substr($hex,0,1).substr($hex,0,1));
      $g = hexdec(substr($hex,1,1).substr($hex,1,1));
      $b = hexdec(substr($hex,2,1).substr($hex,2,1));
   } else {
      $r = hexdec(substr($hex,0,2));
      $g = hexdec(substr($hex,2,2));
      $b = hexdec(substr($hex,4,2));
   }

   return array($r, $g, $b)；
}

同樣也可以將RBG 數組格式轉成16 進制格式。

function wpjam_rgb2hex($rgb) {
   $hex = "#";
   $hex .= str_pad(dechex($rgb[0]), 2, "0", STR_PAD_LEFT);
   $hex .= str_pad(dechex($rgb[1]), 2, "0", STR_PAD_LEFT);
   $hex .= str_pad(dechex($rgb[2]), 2, "0", STR_PAD_LEFT);

   return $hex;
}