YES! The yellow flame of a keroscene lantern produces a green light when shown through the blue-green glass. This color is known as signal-green.
As for the lens, there is a specific style of lens that has been recommened by the Institute for Traffic Engineers (ITE - yes there is a group for everything). KOPP calls these "convex, long-range, wide-angle, prismatic traffic roundels".
http://www.koppglass.com/transportationAndSignalLighting.php
Here's the gateway to all things traffic light on the web:
http://signalfan.freeservers.com/
As for the lens, there is a specific style of lens that has been recommened by the Institute for Traffic Engineers (ITE - yes there is a group for everything). KOPP calls these "convex, long-range, wide-angle, prismatic traffic roundels".
http://www.koppglass.com/transportationAndSignalLighting.php
Here's the gateway to all things traffic light on the web:
http://signalfan.freeservers.com/