The following image is the USB Front Panel Pinout Assignment.
Some of old computer cases have divided the USB front cable. Usually there are 8 cables with a port on each cable. Every port marked with a note: “VCC” for red cable ; “GND” for black cable ; “D+” for green cable ; and “D-” for white cable. If your computer case has this kind of ports, then you should arrange the USB front panel port refer to above USB pinout connection.
Note: do not use long cable to minimize power loss.