What part of "EVACUATE LEFT SIDE ONLY" would the Singapore cabin crew be unable to understand ?
If you are facing the tail, the left side is the Starboard side. If you are facing the nose, the left side is the Port side.
I like the idea of all Green doors on the Port side, and all Red doors on the Starboard side...maybe Black and White would be better for contrast...then "Evac via the ____ (colour) doors ONLY!"
In the airlines I have worked for, the Cabin Crew is trained to look out and asses the situation, and NOT evacuate into a bad scenario, like a fire. BUT, the pax at the overwing exits have no such training...