My computer has three "ports" in the rear, colored pink, yellow and blue. I have a headset with two "prongs".
question: which two ports do I use for the headset?
Is there a risk of damage if I put the prongs in the "wrong" port?
Thanks for your help.
The colours of the headset you are connecting should simply match the ports on the computer.
The three colours you've told me about do not sound like audio ports at all. Those sound like large multipin connectors and yes damage can be caused trying to plug into those with headphone jacks. Pink is the colours of the parallel port (often used for printers), yellow is the serial port, and blue is the VGA port (video/monitor port).
A headset should be using green and pink audio ports. If you have three audio ports, you should see pink, green, and blue. If you have more audio ports, say the computer has surround sound support, there is an orange port, but it is dedicated to rear speakers while using surround sound configurations.
Here is a link to what the audio ports on a computer look like with their colours shown. http://i.stack.imgur.com/AwRgx.jpg
There is more than one layout shown in the picture, but if you look, the pink, green and blue ports are always in the same order and are the original basic inputs/outputs.
In summary, the pink audio port is the microphone input, the green is front speakers/stereo, and the blue is line-in.
In the rare exception to a yellow/orange in colour port that I have seen on an old HP computer is indeed an audio port, but it is an extra and NOT directly a part of the motherboard and it outputs stereo sound PRE amplified for speakers that do not plug into a wall. You can damage regular headphones plugging into this port as too much power will pass through. This HP computer also has the regular pink, green, blue ports as shown in the picture.
Hope this helps you out, have a great day!