core-bundle/src/Resources/contao/classes/StyleSheets.php
protected function convertHexColor($color, $blnWriteToFile=false, $vars=array())
	{
		// Support global variables
		if (strncmp($color, '$', 1) === 0)
		{
			if (!$blnWriteToFile)
			{
				return array($color);
			}
			else
			{
				$color = str_replace(array_keys($vars), $vars, $color);
			}
		}

		$rgb = array();

		// Try to convert using bitwise operation
		if (\strlen($color) == 6)
		{
			$dec = hexdec($color);
			$rgb['red'] = 0xFF & ($dec >> 0x10);
			$rgb['green'] = 0xFF & ($dec >> 0x8);
			$rgb['blue'] = 0xFF & $dec;
		}

		// Shorthand notation
		elseif (\strlen($color) == 3)
		{
			$rgb['red'] = hexdec(str_repeat(substr($color, 0, 1), 2));
			$rgb['green'] = hexdec(str_repeat(substr($color, 1, 1), 2));
			$rgb['blue'] = hexdec(str_repeat(substr($color, 2, 1), 2));
		}

		return $rgb;
	}
protected function convertHexColor($color, $blnWriteToFile=false, $vars=array())
	{
		// Support global variables
		if (strncmp($color, '$', 1) === 0)
		{
			if (!$blnWriteToFile)
			{
				return array($color);
			}
			else
			{
				$color = str_replace(array_keys($vars), $vars, $color);
			}
		}

		$rgb = array();

		// Try to convert using bitwise operation
		if (\strlen($color) == 6)
		{
			$dec = hexdec($color);
			$rgb['red'] = 0xFF & ($dec >> 0x10);
			$rgb['green'] = 0xFF & ($dec >> 0x8);
			$rgb['blue'] = 0xFF & $dec;
		}

		// Shorthand notation
		elseif (\strlen($color) == 3)
		{
			$rgb['red'] = hexdec(str_repeat(substr($color, 0, 1), 2));
			$rgb['green'] = hexdec(str_repeat(substr($color, 1, 1), 2));
			$rgb['blue'] = hexdec(str_repeat(substr($color, 2, 1), 2));
		}

		return $rgb;
	}
Convert hex colors to rgb

@param string  $color
@param boolean $blnWriteToFile
@param array   $vars

@return array

@see http://de3.php.net/manual/de/function.hexdec.php#99478