Dreamcast Guides : CDR Quality Explained in Depth

Pthalocyanine is the most common type of dye. It has a very light green color and is often found in Mitsui/MAM-A blank media and other high-quality CD-R discs. When mixed with other chemical elements, manufacturers sometimes call these “Stabilized Cyanine” or “Super Cyanine” discs. Pthalocyanine appears gold or silver in color, depending on the reflective layer used in the disc.

(Not suggested ever unless testing and going to trash afterwards, but is still harsh on your laser with weak dyes being used)

Cyanine is another type of dye used in CD-R discs. As you may have guessed from the root “cyan” found in the name, cyanine discs are often blue in appearance. It appears as green when used with a gold reflective layer, and it appears blue when used with silver media. These discs are slightly more susceptible to UV damage than pthalocyanine discs, so it’s recommended that they be kept well-protected when not in use.
Finally, Azo dye is used by companies such as Mitsubishi Chemical Corporation and Verbatim Media. Their blank CDs have the best protection against data loss from ultraviolet light and other environmental factors.

(Not the best disc but much better then the above disc and found in higher end store bought CDR's, only use if no means to AZO disc)

Azo dyes typically give the discs a deep blue color, though it can also appear as dark green depending on the reflective layer used.
So which type of dye is best? Unfortunately, there isn’t a universal answer to that question. In general, darker dye indicates a higher quality disc. Many inexpensive CD-R discs on the market have extremely light dye layers. These types of discs are not preferred for storing critical information such as company documents or personal photos.

(As you can see this is by far the superior disc without using the Kodak Gold disc that are for archiving only and don't work in your Dreamcast at all so stick with these and a quality burner at about 16x and you can't go wrong. The disc will last for years and strain your laser much less then the other two dyes. I use these exclusively with Plextor (PX708UF to be exact & PX 504UF bith at 16x everytime) drives to record the data and have disc that are 5-8 years old and work just like the first day they were created))