The idea of gelling your flash for effect has been a topic here a few times. I most often use gels on my flash to correct my flash when working with tungsten / incandescent light. There are times though when I gel my flash just for effect, creating a shift between my foreground (lit by gelled flash) and my background.
In the examples shown in the several articles here, there wasn't the type of background where the effect can clearly be seen on easily recognizable "neutral" background. In the article turning day into night, we turned Read more inside...