I have coby csp 96 (i just buy it) and i need to know how can install to my pc wich have just three colors green orange and pnik or if i have to buy a external sound card?

Check the speakers connection and that should give you at least 8 of the colors. The ones left then are going to be ground and power and display power. You can figure those out with a meter.

http://www.cobyusa.com/files/manuals/CSP94_MN.pdf

The green version is all that this vehicle requires.In 96 GM switched to Dexcool "orange"or extended life coolant.

Couldn't find the CSP-94 but CSP-96 is available at retrevo.com for free. It may work out for you.

1996 Ford Thunderbird Car Stereo Radio Wiring Diagram
Radio Constant 12V+ Wire: Black/Orange
Radio Ignition Switched 12V+ Wire: Yellow/Black
Radio Ground Wire: Black/Light Green
Radio Illumination Dimmer Wire: Light Green
Radio Antenna Trigger Wire: N/A
Radio Amplifier Trigger Wire: Dark Blue
Front Speakers Size: 5′ x 7′
Front Speakers Location: Doors
Left Front Speaker Wire (+): Orange/Light Green
Left Front Speaker Wire (-): Light Blue/White
Right Front Speaker Wire (+): White/Green
Right Front Speaker Wire (-): Green/Orange
Rear Speakers Size: 5′ x 7′
Rear Speakers Location: Side Panels
Left Rear Speaker Wire (+): Gray/Light Blue
Left Rear Speaker Wire (-): Tan/Yellow
Right Rear Speaker Wire (+): Orange/Red
Right Rear Speaker Wire (-): Brown/Pink

The green, black and beige cable is non-standard and proprietary meaning that Coby has defined their purpose which hopefully is described in your user guide. It would be worth a few dollars to buy the properly color-coded cables to uncomplicate your setup. Buy cables (or cable sets) that have the same color coding as your TV jacks along with the cable suggested below.
There are several ways to connect to an HDTV system and these are normally standard as previously described.
The red and white are for right and left channels and it isn't uncommon to see a three cnductor cable with one not connected since one of the methods of connection is to supply audio via two cables, video (composite) via a 3rd which is plugged into a corresponding jack, normally colored yellow. Audio cables aren't really required to carry the mix of much higher frequencies of composite video.
If you have the following connectors, try this:
- S-Video (this does not contain any audio information and requires an S-Video cable) - Right (red) and left (white) audio paths.    The S-Video connection provides a better signal that gives you a noticeably sharper picture. This setup is selected from the TV's input source menu.   

This should all be described (at least in Chinglish) in a user guide.
For sure, two of the threesome cable are right (red) channel and left (white) channel. The remaining one probably for center or rear.  Mostly all of the different pieces should have color-coded in- and output jacks.

Look at the connector legends printed on your devices, they should have markings such as "line" both in- & out- and you will find corresponding markings on each.
You would need the 'out' connections from either the DVD and TV to end up on the 'in' connectors of the Coby main unit, presumably the woofer cabinet since these mostly house the electronics; i.e. power supply and amplifier.     

1986-89 Lincoln Mark VII Stereo Wiring Constant 12V+ Green/Yellow Switched 12V+ Yellow/Black Ground Red Illumination Blue/Red Dimmer n/a Antenna Trigger Orange/Blue Antenna Right Rear Front Speakers 6 1/2" Doors Left Front (+) Orange/Green Left Front (-) Black/White Right Front (+) Pink/Blue Right Front (-) Black/White Rear Speakers 6" x 9" Rear Deck Left Rear (+) Pink/Green Left Rear (-) Blue/Orange Right Rear (+) Pink/Blue Right Rear (-) Green/Orange

You have a green orange and black connection, hook those to the subwoofer, on the other end of each of those connections is a split connection which splits to a Red/White cable that is provided, correspond the red/white to your dvd unit as such (Front Left, Front Right, Surround Right, Center and Sub), if your dvd player only has a 1 white/red port then you will only be able to use the 2 chanels, so just 1 split will be required.

I need help hooking my speakers to my computer