$green2 = hexdec(substr($rgb2,2,2));
$blue2 = hexdec(substr($rgb2,4,2));
- return abs($red1 - $red2) + abs($green1 - $green2) + abs($blue1 - $blue2) ;
+ return sqrt(pow($red1 - $red2, 2) + pow($green1 - $green2, 2) + pow($blue1 - $blue2, 2)) ;
}
function closest_colour($rgb, array $colours) {