While primarily used to transmit high quality video from a video device like a DVD player to a television, component video cables are technologically no different that standard red, white and yellow RCA composite cables, which carry stereo audio and lower quality video. This means that if you are in need of RCA composite cables, but happen to have some component video cables laying around, you can actually use them to connect your devices and transmit audio and video to your television.
Connect your component video cable to the RCA inputs on your video device. Component cables are colour coded red, blue and green, instead of the RCA composite cable red, white and yellow. To adjust you need to decide which component colours are going to represent composite colours. Plug the red component plug into the red RCA output on your device. Plug the blue plug into the white output and plug the green plug into the yellow output.
Plug the other end of the red cable into the red RCA input on your TV. Plug the other end of the blue cable into the white RCA input and the green cable into the yellow RCA input.
Turn on your video device and your TV. Use your TV's remote to switch the RCA input into which you plugged your video device. You should have audio and video running to your TV and your will see an image on-screen and have sound coming through your TV's speakers.
Component video cables are typically thicker with higher-quality construction, so you may actually see a small performance boost by using them.
This doesn't necessarily work as well the other way around, as the white and red cables on composite cables are not always high enough quality to carry a component video signal.