Rosco Roscolux #312 Filter 20 x 24″ Sheet (Canary Yellow) Roscolux is widely recognized as the most versatile range of color, correction and diffusion filters for entertainment lighting. Originally introduced in the United States, it is now available all around the globe. Roscolux is comprised of two types of body-colored plastic filters; extruded polycarbonate and deep dyed polyester, both of which provide superior consistency and durability when installed in front of hot theatrical and film/TV fixtures.