 Additionally they may add gel to color the light, patterns (or gobos) to create texture or shape a light into pictures, and accessories that give the designer the ability to change some aspect of the light, such as scrollers (color changers) or pattern effects (gobo rotators).In the past (and even in some theatres today) the electrics department was in charge of all water and water effects used on or offstage (i.e.rain, waterfalls, pools, etc.