l recently installed an after-market stereo in my xB, however there is extra wires that were not used with the new stereo, so can anybody identify the different colored wires and their purpose?

l can not name them off, but l can give you a suggestion, a trick l used to replace my stereo. you can get the interface at most stereo stores. l got mine at wal-mart years ago. this piece resembles the connector at the back of your radio. match the wires up between this and the connector on the new radio, and plug them in. hope this helped...

First you cannot just put another stereo in. The speakers are amplified and you need a kit to turn off or blow head unit. they are a pain but wire coding means little since nowadays stereo is in newer cars are proprietary.

Get your self the interface kit as suggested above got mine at Best Buy for about $20

Hope these help.
TOYOTA

P o w e r
Memory (+12v Constant) Blue/Yellow
Ignition (+12v Switched) Gray
Ground (-) Brown
Illumination Green
Dimmer White/Green
Power Antenna Black/Red
S p e a k e r s
Right Front (+) Light Green
Right Front (-) Blue
Left Front (+) Pink
Left Front (-) Violet
Right Rear (+) Red
Right Rear (-) White
Left Rear (+) Black
Left Rear (-) Yellow

while the last answer was correct. there is no onboard amps for the stock speakers!!! l changed my hu 2 days after l got it. now if ur talking about the wiring harness to connect to the stock vehicle wiring then yes u need one of those. but the wires left over is an illumination wire think its orange. & that extra 4 or 5 wires would be for the steering wheel controls. if not there is an extra blue wire off the back of the hu that needs tto be hooked up to the blue wire that says power antenna or u will get crappy radio reception. if u have any other ? importracingtr.com