Well, since we're on an audio discussion site, if you really feel the need to be green maybe the following would be a start.
> Don't buy, make or use speakers with less than 100 db anechoic sensitivity.
> Limit all of your amp's input power consumption to 10 watts maximum.
> Always unplug all of your audio equipment when not in use.
> Reduce all HT/music systems to 5.1, isn't that really enough?
> Dim all displays when possible.
Steve
P.S. And bring back the Yamaha orange display, I "believe" it was a more energy friendly color.