Will changing the color of the light source change the apparent brightness on a traffic light? Let's say you have a traffic light with the well known red, yellow, and green tinted glasses. 


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*Setup 1: Each glass has a white light bulb behind it.

*Setup 2: Each glass has a colored bulb behind it which matches the tint on the glass. So there is a red light behind the red glass, a yellow light behind the yellow glass, and a green light behind the green glass.


Assuming all the light bulbs -white and colored- have the same power specs, which setup would appear to be brighter to the human eye?
 A: We have to differentiate between radiant flux and luminous flux. The former refers to power carried by all emitted photons (Watts) while the latter refers to brightness as perceived by the human eye (Lumens). 
With that out of the way it is clear that by using filters to change the perceived color is equivalent to wasting all the luminous flux associated with the unwanted wavelengths as filters work by absorption. So if there was a way to produce only the desired wavelengths so that filters are unnecessary then for the same amount of power in, there is more useful power out. 
The problem is that filament based lighting produce a continuous spectrum of wavelengths and must be filtered to produce specific colors. Fluorescents and LEDs actually produce at least 3 individual colors from phosphors/dopants respectively. This is why the latter 2 technologies tend to be more efficient--they don't have to produce true whites, don't produce significant IR, and yet their light is still perceived as white. Of course, if we obtain single phosphor fluorescents or single die LED, these will always be more energy efficient than to use 3 phosphors only to filter 2 out. 
Additionally, luminous flux pertains to the biology of human eyes, which have been estimated to be most sensitive to 555nm (green) and taper off at red and blue. This means a pure red lamp producing 5W radiant flux of 600nm light doesn't appear as bright as 5W radiant flux of 555nm light. 
A: Setup 2 will be definitely brighter (at least 3 times), if colored lamps are color LED or color fluorescent (even if we ignore their intrinsic higher efficiency) as only "correct" photons are generated, and very little losses on the filters.
If these "colored lamps" are usual light bulbs with colored surface (i.e. with integrated filter) - efficiency would be roughly the same for both variants. 
