Is there something about the color used that makes a CD writable? What makes it different from a regular CD?
Factory produced CDs are stamped out. The data is stored on pits and lands (ie bumps on the polycarbonate disc). Aluminum is used to make the surface reflect the laser light.
Recordable CDs have a photosensitive dye coating that the write laser changes the color of when it burns to record data. The read laser reads the different colors as the data points.