Colored lighting is often used in theater to create a particular atmosphere. It can create visual interest in an otherwise plain scene. Colored lights also are a common component of special effects. Various methods exist for using colored lights effectively.
Depth
Plain lights can make a scene appear flat, which is usually undesirable. Stage performances almost always use colored lights to add depth to a scene. The most common technique of this type uses a light with a warm color and a light with a cool color, such as light blue and light yellow. The warm color appears to be the light and the cool color appears to be the shadow. Each colored light is placed at a different angle, which creates a layered visual effect.
Intensity
Colored lights typically use subdued colors in order to avoid overwhelming the natural colors of the actors and the scenic elements. The mild colors of the lights should merely add a different tint to the colors already in the scene. Green is not typically used for foreground lighting, since it makes the actors’ skin look sickly. The primary exception to this rule is the use of intense colors in special effects, where you want the effect to dominate the scene.
Background
Background illumination frequently requires lights with different colors from those used for foreground lighting. The use of lights with two colors in the background provides the appearance of different light sources. This technique also provides visual contrast with the foreground.
Natural Lighting
The colors used to provide the appearance of natural lighting are different from the colors that are actually in natural lighting. Sunlight has some blue light in it, but intense yellow and orange lights are used to simulate sunrises and sunsets on stage. A night scene uses light blue lights in combination with dark blue or indigo lights to suggest moonlight.
Fire
Colored lights can simulate firelight in a variety of ways, although pure yellow lights are almost never used for this purpose. The most common choices for fire range from amber to deep red. The hottest fire should have be amber and dim fires should be deep red. The depiction of firelight is one of the rare occasions where it may be appropriate override the stage’s natural coloring.