[Gr1m]

well on car radios:
black gets grounded
yellow gets constant 12v
red gets ignition 12v
pink really depends on what type of head unit. it could be for illumination. if this is the case, you could just jump the pink line into the red ignition line if your too lazy to tap into a cubbyhole/headlight triggered line.

have you seen this headunit work in another car? it could be shot since I doubt hooking up those wires will make a difference. it looks like those actually come off the car side of the harness so if you connect those to the car it wont change your radio situation.

it doesn't really sound like you know what your doing so maybe you should take it to a shop before you start hacking up your stock harness.