Lighting of skycloths is one example of the effect of colored light on scenery. Backdrops are customarily lit by groups of three or four cyc lights which are luminaires designed for that purpose. These are often used with filters in the three primary colors: blue, green and red, or in four colors: the three primaries (red, green and blue) and an additional
color wash
in yellow or a lighter blue. Different relationships between the three primary colors, achieved by different intensities of the cyc lights can produce a multitude of colors .
A mixture of all three at full intensity will produce white light. Another favorite color scheme mixes the three secondary colors: yellow, blue-green and magenta. Sometimes an orange or an amber is used instead of the yellow, and when a fourth wash is available, a deep blue is usually added.
Backdrops or cycloramas in theatre are usually a light blue or gray. This kind of backdrop reflects the blue part of the
spectrum
better than the green-red part, thus compensating for the low
transmission
of the dark primary blue filters.
