Show dictionary · Lighting
Gel (Color Filter)
Also: color · filter
A gel is a flexible colored filter sheet placed in a frame in front of a lighting fixture to color the beam. The name survives from gelatin originals; modern gels are heat-resistant polyester, sold in numbered manufacturer systems like Roscolux and Lee.
In practice
The numbers are the language: L201 is a Lee color correction blue, R26 a Roscolux red, and designers specify plots by these codes. Beyond color, the same product families include diffusions (frosts, silks) that shape beam quality rather than hue.
LED color mixing has eaten most of gel’s traditional territory, but gel persists on tungsten rigs, in color-correcting practicals and camera lighting, and in the muscle memory of every electrician who has cut sheets into frames on a road case at midnight. Cut lists (which colors, what sizes, how many) remain a working document on tungsten-heavy shows.
How you’ll hear it
"Re-gel the balcony rail to L201; the follow spots are reading too warm on camera."
Related resources
Part of the eventools.io Show Dictionary, a free glossary of live event production terminology.