"read it in a book that ’costs money?’
You do realize that sounds like, "I read it on the internet." Right?
Oh dear. Philips produced a series of technical engineering specifications for the CD and successive variations including SACD. Each specification was given a distinct cover colour, and the specification became colloquially known by the colour of its cover. The specifications contain valuable intellectual property and are usually available from standards bodies
Standards Bodies (Official Source): The original Red Book standard is officially known as IEC 60908. You can purchase official versions from:
- The International Electrotechnical Commission (IEC)`.
- ISO (International Organization for Standardization)}
The Rainbow Books are a collection of standards created by Philips that define the allowed formats of Compact Discs. This list is an extract from the original article at http://en.wikipedia.org/wiki/Compact_Disc
Red Book
- CD-DA – Digital Audio extended by CD-Text
Yellow Book
- CD-ROM – Read-Only Memory and CD-ROM XA
Orange Book
- CD-R alias CD-WO or CD-WORM – Recordable, Write Once or Write Once, Read Many
- CD-RW alias CD-E – ReWritable or Erasable
- CD-MO – Magneto-Optical
White Book
- VCD – Video and
- CD-Bridge - Hybrid discs, e.g. CD-Ready
Blue Book
- E-CD – Enhanced,
- CD+ – plus and
- CD+G – plus Graphics (karaoke) extended by CD+EG / CD+XG,
Beige Book
- PCD – Photo (not Picture)
Green Book
- CD-i – interactive
Purple Book
- DDCD – Double Density
Scarlet Book
- SACD – Super Audio
By way of comparison, the internet is remarkably free from formal standards. Almost all its features have been initiated as Requests For Comment.

