you could buy a repair manual for around 20 dollars that will tell u and you will have a reference for other problems in the future. the radio should have a diagram on it.
if worse comes to worse u could buy and learn how to use a multimeter there should only be three power wires, one constant 12v. the next switched which powers when u start the car or have it in the acc position and the ground.
hopes this helps but decks usually have red yellow and black for the hookup wires and the speaker wires are usually two colored like u mention.
