I'll let someone else handle your second question, but I can answer this one.Prius Fan said:
Green is Good! It means that you're holding a nearly full charge on your battery.
Someday you'll be driving around and notice that it turns pink and is only two bars from the bottom, that means that the battery is nearly empty. Not to worry, the engine will cycle on and make some power for ya!
I've found that it's easier to get into "stealth" (electric only mode) easier when the battery is green.
Happy driving.