Multimode fiber optic cable markings

Multimode fiber optic cables are marked using standardized color codes, printed fiber counts, fiber types (OM1–OM5), and jacket specifications to ensure proper identification and compliance with TIA/EIA-598-C standards.

Fiber Color Coding

Multimode fibers follow the TIA/EIA-598-C color code, which assigns a specific color to each fiber within a cable. The standard 12-color sequence is: Blue, Orange, Green, Brown, Slate, White, Red, Black, Yellow, Violet, Rose, Aqua. For cables with more than 12 fibers, the sequence repeats, often with additional markings such as stripes to maintain unique identification for each fiber . High-density cables may use a tube-and-fiber system, where the 12-color sequence is applied to each buffer tube, and fibers inside the tube are also color-coded. For example, fiber #34 in a 48-fiber cable could be the 10th fiber (Violet) in the 3rd tube (Green) to ensure precise identification .

Jacket Color and Fiber Type

The outer jacket color provides a quick visual cue for the fiber type:

• OM1: Orange jacket, 62.5/125 µm core
• OM2: Orange jacket, 50/125 µm core
• OM3: Aqua jacket, 50/125 µm, laser-optimized
• OM4: Aqua jacket, 50/125 µm, enhanced laser-optimized
• OM5: Lime green jacket, 50/125 µm, wideband multimode fiber (WBMMF) for SWDM applications The fiber type (OM1–OM5) is usually printed on the jacket for confirmation, especially when jacket colors are similar (e.g., OM3 vs OM4 both use aqua).

Printed Markings on the Cable Jacket

Multimode fiber cables typically include the following printed information on the outer jacket:

• Fiber count: e.g., "12F" for 12 fibers, "24F" for 24 fibers
• Fiber type: OM1, OM2, OM3, OM4, or OM5
• Manufacturer and part number: for traceability and inventory
• Fire rating: OFNR (Riser), OFNP (Plenum), OFNG (General Purpose), LSZH (Low Smoke Zero Halogen)
• Compliance standards: ISO, IEC, UL, or other certifications
• Cable length and manufacture date: for installation planning and warranty tracking

Connector and Termination Markings

Connector colors also indicate fiber type and polish:

• Blue: UPC (Ultra Physical Contact)
• Green: APC (Angled Physical Contact) These markings are critical to prevent misconnection and ensure proper optical performance .

Summary

Multimode fiber optic cable markings combine color-coded fibers, jacket colors, printed fiber counts, fiber types, manufacturer info, fire ratings, and compliance standards. Following the TIA/EIA-598-C standard ensures accurate identification, reduces installation errors, and supports efficient maintenance and troubleshooting in enterprise, data center, and telecommunications networks .