Yellow is the universally adopted TIA color code for OS2 (Single Mode) fiber because it offers the lowest intrinsic fiber optic attenuation and is used for the longest reach. The distinct color immediately alerts personnel that the cable is designed for long-distance, high-power. But with thousands of fibers in a single cable, color coding is your universal translator. Without it, you'd be lost in a spaghetti mess of glass. However, there are key differences that matter both technically and commercially. Patch Cord: Connector on both ends (e. A pigtail fiber indicates a short length of optical fiber cable that has a pigtail connector (for example, SC, FC, ST, LC, etc. The color of the outer sheath of the multimode pigtail is orange, the wavelength is 850nm, and the transmission distance is 500m, which is used for. Connector colors serve two distinct purposes: identifying fiber type and identifying the ferrule polish angle.