private function _writeSheetLayout()
	{
		if (!$this->_phpSheet->isTabColorSet()) {
			return;
		}

		$recordData = pack(
			'vvVVVvv'
			, 0x0862
			, 0x0000		// unused
			, 0x00000000	// unused
			, 0x00000000	// unused
			, 0x00000014	// size of record data
			, $this->_colors[$this->_phpSheet->getTabColor()->getRGB()]	// color index
			, 0x0000		// unused
		);

		$length = strlen($recordData);

		$record = 0x0862; // Record identifier
		$header = pack('vv', $record, $length);
		$this->_append($header . $recordData);
	}