Polarized Plastic

I got this idea out of a book called Camera Creative by Chris Gatcum. It is a good book if you are looking for new projects to do with your camera. The way you make these look like this is with your polarizing filter. I placed various pieces of clear plastic objects in front of my laptop monitor (it's important that your light source be an LCD screen). I opened a window on my laptop so that the light being projected was white, and then placed the polarizer on the lens and rotated it around so that I could see all the rainbow colors in the plastic. All of these are straight out of the camera with out any editing done on them. Even though the background on the second photo down is orange brown, it is the white screen from my laptop. That's what color it changed to with the polarizer.