Green is good, right?

I came out from Chinese Choir rehearsal on Friday night and saw this sign at the school across the street. Apparently it was designed by the students. The plural of gas is gases, and the ones coming from cars are not green.

[Mike Schwandner]

lol it is worse to keep turning the car on and off lol

[Wyoming Tree Planter]

The gas from my car is blue! :)