What's the deal with coloring CD's and/or tray mechanism

As I said you can see for yourself with a red laser poster how much is reflected off the black tray.nalso, of the black matte tray was actually 100% effective the green pen wouldn’t make any difference.

It doesn't, according to many.  You are trying to make up theory based on some silly tweak, that according to many doesn't work at all.

the reason you see the infrared is because it’s near infrared next to the visible part of the spectrum thus part of the signal is in the red zone.

 No, spectrum of the infrared emitting diode is very narrow and it does not project white light.  You still cannot see it with naked eye.  The portion that you can see if you look directly into transmitter will be dark red.  The reason camera can see it is because camera sensors are sensitive to infrared up to around 1100nm.  You see white light because red green and blue sensor filters are not very strong and all of them pass some infrared.

"Other colors are used only to reflect only one color."

I don’t think we’re on the same page. You want to absorb color not reflect it. For a given color there is a complementary absorbing color. 

You still don't get it.  Perhaps this drawing will help you:
http://archive.cnx.org/resources/b3c8a8818e60b70ff638c267249826b1e5c0747f/Figure_27_03_02.jpg

The bandwidth of the laser is not narrow. It’s actually fairly wide, certainly not monochromatic. As is the photodetector bandwidth. That’s why red scattered laser light gets into the detector. Neither one is monochromatic. And that’s precisely why the CD laser appears RED even though it’s wavelength is 760 nm. Which is invisible. Hel-loo! I must be smarter than those other people you’re listening to. You’re following the wrong sheep.

As I explained earlier - spilled light would appear as mostly red but it shows as white (no red at all), because all camera sensors can see infrared and filters are not able to filter it completely. If you cannot understand it I cannot help it. Also LED transmitters have narrow band, like this one: http://www.vishay.com/docs/81009/tsal6100.pdf

As you can see there is no light emitted below 840nm (Fig. 8) while visible light ends at 750nm. If you compare two cameras one with the film and another with digital sensor set to the same sensitivity you’ll find that infrared won’t be visible on the picture made with film camera but will show as white light on the one with digital sensor. It is not because of "spilled" light but because digital sensor is sensitive to infrared and film isn’t. I’m not sure if your understanding of this is as poor as one of the class D amps, but it is getting close. No sense to discuss it any further.

kijanki
"As I explained earlier - spilled light would appear as mostly red but it shows as white (no red at all), because all camera sensors can see infrared and filters are not able to filter it completely. If you cannot understand it I cannot help it. Also LED transmitters have narrow band, like this one: http://www.vishay.com/docs/81009/tsal6100.pdf

As you can see there is no light emitted below 840nm (Fig. 8) while visible light ends at 750nm. If you compare two cameras one with the film and another with digital sensor set to the same sensitivity you’ll find that infrared won’t be visible on the picture made with film camera but will show as white light on the one with digital sensor. It is not because of "spilled" light but because digital sensor is sensitive to infrared and film isn’t. I’m not sure if your understanding of this is as poor as one of the class D amps, but it is getting close. No sense to discuss it any further."

We are not on the same page. Not even close. I define infrared light as above 700 nm. Therefore if there is red in the CD laser light it MUST be because the 760 nm nominal wavelength is NOT monochromatic. It has SOME RED light in it. And that RED LIGHT has wavelenths BELOW 700 nm since that is where visible light ENDS. This conversation can serve no purpose anymore.