How to change charger LED color on MacBook Air
I don't think that it could be possible to "change the color" of charger plug led easily without destroying it. It's hardwired. If you are good enough to work with soldering iron under microscope you could.

Here is a teardown: http://www.cqdx.ru/ham/do-it-yourself/diy-repair-the-mac-book-pro-l-type-power-supply-plug/