public static function rgba( $hex, $percent ) {
		$hex = static::_hex_normalization( $hex );
		$rgba = [];

		for ( $i = 0; $i < 3; $i ++ ) {
			$dec = hexdec( substr( $hex, $i * 2, 2 ) );
			$rgba[] = $dec;
		}

		$rgba = implode( ',', $rgba );
		$rgba = "rgba({$rgba}, $percent)";

		return $rgba;
	}