What do the colors mean?

• Grey: Well below target. (Also, waiting for valid power, GPS, or an active plan.)
  

• Blue: Below the target range.
  

• Green: Within the target range.
  

• Orange: Above the target range.
  

• Red: Well above target.
  

The on-target range uses a small watt floor plus a percentage band, so low-power and high-power targets both behave sensibly.