If you are working on a web app that does things with colours then you could find it useful to have function to convert between different colour types. Here is a PHP snippet which allows you to convert HEX colours to RGB colours. All you have to do is pass in the HEX colour as a parameter and it will return the RGB values as an array.

function hex2rgb($color)
{
    list($r, $g, $b) = array($color[0].$color[1],
                             $color[2].$color[3],
                             $color[4].$color[5]);
    $r = hexdec($r); $g = hexdec($g); $b = hexdec($b);
    return array($r, $g, $b);
}

#Improved Version

Here is an improved version of the above function to convert Hex to RGB thanks to Michael Kaiser. This function allows you to send in 6, 3, 2 or 1 digit Hex colours to the function and will still convert it to RGB.

function hex2RGB($hex) 
{
        preg_match("/^#{0,1}([0-9a-f]{1,6})$/i",$hex,$match);
        if(!isset($match[1]))
        {
            return false;
        }

        if(strlen($match[1]) == 6)
        {
            list($r, $g, $b) = array($hex[0].$hex[1],$hex[2].$hex[3],$hex[4].$hex[5]);
        }
        elseif(strlen($match[1]) == 3)
        {
            list($r, $g, $b) = array($hex[0].$hex[0],$hex[1].$hex[1],$hex[2].$hex[2]);
        }
        else if(strlen($match[1]) == 2)
        {
            list($r, $g, $b) = array($hex[0].$hex[1],$hex[0].$hex[1],$hex[0].$hex[1]);
        }
        else if(strlen($match[1]) == 1)
        {
            list($r, $g, $b) = array($hex.$hex,$hex.$hex,$hex.$hex);
        }
        else
        {
            return false;
        }

        $color = array();
        $color['r'] = hexdec($r);
        $color['g'] = hexdec($g);
        $color['b'] = hexdec($b);

        return $color;
}