It’s not green if:

• it’s always on and using full energy requirements (even if it uses less energy than a previous model)
  Some systems can’t be turned off, even if they are only used (on average) five minutes a day because they have to monitor for, and respond to, exceptional events. But if they draw the same amount of power whether they are performing a function or just listening for a signal, they aren’t green. A green system will sleep when not required, and wake up when a signal is received, and in the case of computers, utilize only a fraction of full power to maintain the contents of active RAM.
• production or disposal is less environmentally friendly than other options
  Truly green products do not contain hazardous materials and are designed so that they are easily recycled or the raw materials are easily reclaimed for future reuse. In addition, the production should require less power and water than previous generations.
• you simply install new software on old, energy hogging, hardware
  Taking an old PC with a 300 watt power supply and installing Linux does not make it green.

and, finally, it’s not green if:

• it’s painted green
  Taking an old product and painting it green does not make it green!