I purchased DVD±R/W LiteON but maked some mistake, I chose light color. I heard that black drive(inside) is better, since has less reflection, this important for high quality burning..
I've never heard that and doesn't make any logical sense considering the real-world construction of drives. I think someone is playing a joke on you.
I meant plate where DVD does, not front panel color. If you look inside some models, you'll probably find that plate is black color(I forget what model, it seems some of Benq).
Again, I don't think that has any real bearing. Any laser light is highly collimated and focused on a small spot on the disc. Any reflectivity coming back is going to be at reduced intensity and with a wider spread (less collimated), effectively reducing laser strength immensely. Any further reflection, such as off the tray, will be relatively nothing, no where near enough in intensity to affect playback or burning. Not that it matters anyway; considering the construction of DVD players and burners, I doubt the tray actually sees anything, so there would be no reflectivity in the first place.