The outer sheath color of multimode fiber optic patch cord can be divided into multiple colors, OM1 and OM2 are orange, OM3 is aqua, OM4 is violet, and OM5 is lime green. Each coloration is a type of cable or has a special use. It's like naming each and every one of those cables so that way we can easily see which one we're dealing with and put. As we all know, different colours of the outer jacket of a fibre patch cord represent different types of fibre optic patch cord. The most critical piece of performance data on your 400G network doesn't come from an OTDR trace—it comes from. Color codes are used in fiber optics to identify fibers, cables and connectors.