Warm and cool lighting

[majere]

I am wondering why in stage lighting you are supposed to hit an area from two angles with both a cool and a warm color. Isn't it easier to just use a completely neutral color all the way around? (such as surprise pink)

I'm sure their are very good and proven reasons for lighting the stage this way but I just can't rap my head around it. Any explanations?

[Les]

well one reason would be that it allows a designer to completely control a scene's warmth or coolness. When you're using say, No Color Blue (R60) and Light Bastard Amber (R02), if the director would like the scene warmer, instead of raising all the intensities, you can just add amber or subtract blue. That way, the lighting level is consistent, however the scene appears warmer - not brighter. Also, when warm and cool colors are mixed, it appears on stage to be a crisp, white light (or it should). This reaction sets off the little hints of color in stage makeup, sets, and costumes. One neutral color would tend to wash things out and give everything one tint. Not to mention, you would likely lost a lot of depth perception.

[jbeutt]

that's true, but having two colors has a lot to do with shadows and contrast as well. If you used only one color, the shadows on one side would simply be filled in with the same color and you'd get a washed out flat appearance to the actors. With two colors, there is a depth and dimensionality added by applying opposing colors from two sides. They'll mix together in the open, flat surfaces of the face, but shadow areas, while still lit, will only be lit by one of the colors. The shadow will also be controlled as opposed to using single-source lighting where you get long annoying shadows.
Depth and contrast is really important to consider when you're lighting. Many times it's just R5 opposite R60 that's needed to make the actors pop. If it were all one color, not only would you lose control of the color on stage, you'd be giving up many important shadows and therefor any depth.

[Les]

Yes, and also keep in mind that there are many variations on the "right" two colors for the job. In most cases, it depends on the show you are designing. Some shows may call for a more sepia appearence where amber would be a dominant color, while other shows may prefer a no-color pink. Usually this is clerified by the type of show it is (Straight Play, Musical, Period, Stylistic, Drama, Etc...) There are no two colors that you can put in your lights and expect to meet the needs of every performance. Sometimes R05 is better than R02, sometimes not. Just depends on your particular venture. Just avoid using a solid color, because you will get caught with your pants down sooner or later, and for the love of God, do not leave the lights white. That's just gross.