I have a question about my cars audio system?

i have a 1984 pontiac firebird and im trying to upgrade my old cette player in it into a regular CD stereo. However i have no idea what wire colors go where (and since i need to know this to install the CD stereo its quite frustrating) but the old cette player company is called Delco sound system. Can anyone tell me or tell me where i can find out the color codes for my cars audio (and its not in the owners manuel)