Red and white for front speakers; black and yellow for the rear and sub (assuming you have Bose setup)
As said above, the sub is fed by the same output as the rears.
Make sure you have the blue wire connected, this is the remote power on for the amp.
If all is working except for the sub, try checking you don't have a high pass filter set - this would stop the rears receiving low frequency sounds ie bass that the sub would play.