Check on the electrical capacity of the room. Depending on where the theatrical lighting is being mounted and how many lighting instruments are being used, there must be enough wattage and capacity to run the system. Be sure that whatever instruments you are using can be serviced by the building's electrical capacity. Always use grounded, heavy duty electrical cables.
Choose lighting instruments. There are several types of lights used for stage lighting. Ellipsoidals, PARs, and fresnel lights are the most common types and all usually come with a mental frame where filters can be placed for effect. For a complete list of available instruments, visit the Stagelightingprimer website.
Choose the correct type of gel. Gels are thick plastic squares placed in front of the lighting instruments to help achieve an effect in theatrical lighting. Some are made in a tubular format so they can be fitted over fluorescent lights. They can be combined to attain multiple focal points on stage, or to create an overall warm or cold feeling to the stage environment.
Create a color scheme. Gels come in thousands of colors and can be purchased in individual squares, in rolls, or in tubes. Deciding on which colors to use on stage to achieve a specific effect will determine which colors to purchase.
Attach the colored gel to the lighting instrument. For most standard theatrical lighting, a gate or shutter -- a metal plate attached to the instrument -- holds the gel in place. Once the lighting instrument is hung and focused, the gel should spill color onto the stage and the effect should be achieved.