Kneeling behind my equipment stand the other day, holding a MagLite in my mouth (wish my receiver had a USB port for a light like the new Axiom subs do!), I was trying to change some of my speaker connections when I noticed that none of the usual red/black color codes for positive and negative terminals for the various channels applied. Instead, there was an array of different colored binding posts, only one of which was red (the positive connector for the right front main speaker). Though my A/V receiver is two years old, I'd forgotten that it has the new Consumer Electronics Association color coding for each speaker channel, intended to help newbies (as well as oldies) identify which channel is which when you are doing the speaker or cable hookup for a 5.1-channel (or more) surround sound system.
A good idea, but you'll need the following color code to identify each channel unless you have your owner's manual handy. If your receiver has been manufactured in the last couple of years, there's a good chance it will conform to the new color scheme. In addition to the speaker binding posts, the RCA preamp outputs, the Subwoofer Output, and the multichannel analog preamp inputs also conform to the same colors.
For speaker binding posts, the negative terminal (-) is always black, whereas the positive terminal (+) will have a different color corresponding to each channel of the surround system. If you find this confusing, note the positive (+) and negative (-) polarity for each pair of binding posts. The new color code is:
Front Right speaker: Red
Front Left speaker: White
Center Channel: Green
Left Surround (side): Blue
Right Surround (side): Gray
Left Back Surround: Brown
Right Back Surround: Tan
Subwoofer Line-Level Output (RCA): Purple