Using 8 way cables all the time, I have been wondering for years if there is any recommendation or standard for what color goes where. The other day I accidentally bumped across a proposal from the German Surround Sound Forum, referenced in table 4.1 in Rumsey (2001)1:
| Track | Signal | Comments | Colour |
| 1 | Left | Yellow | |
| 2 | Right | Red | |
| 3 | Centre | Orange | |
| 4 | Low Frequency Enhancement | Additional sub-bass and effects signal for subwoofer, optional | Grey |
| 5 | Left Surround | -3 dB in the case of mono surround | Blue |
| 6 | Right Surround | -3dB in the case of mono surround | Green |
| 7 | Free use in program exchange | Preferable left channel of a 2/0 stereo mix | Violet |
| 8 | Free use in program exchange | Preferable right channel of a 2/0 stereo mix | Brown |
1 F. Rumsey (2001): Spatial Audio. Focal Press
Update (2010-07-14):
Pascal Baltazar pointed me to a Wikipedia article on surround sound that provides a different color code, quoting the ANSI/CEA-863-A standard from 2005:
| Track | Signal | Colour |
| 1 | Front left | White |
| 2 | Front right | Red |
| 3 | Center | Green |
| 4 | Low frequency | Purple |
| 5 | Surround left | Blue |
| 6 | Surround right | Grey |
| 7 | Surround back left | Brown |
| 8 | Surround back right | Khaki |
