The outer sheath color of a fiber optic cable indicates the fiber type and application according to the TIA-598 standard, with single-mode fibers typically yellow and multimode fibers using orange, aqua, violet, or lime green.

Outer Jacket Color Coding

The outer jacket (sheath) color is a visual identifier for the type of fiber inside the cable, helping technicians quickly distinguish between single-mode and multimode fibers during installation and maintenance . Common TIA-598 color assignments include:

• Single-mode fibers: Yellow
• Multimode fibers:
  • OM1: Orange
  • OM2: Orange or black
  • OM3: Aqua
  • OM4: Violet
  • OM5: Lime green For hybrid or multi-fiber cables, the outer jacket may also include printed legends indicating fiber count and type to provide additional clarity .

Inner Fiber and Tube Color Coding

Inside multi-fiber cables, individual fibers are color-coded using a 12-color sequence (Blue, Orange, Green, Brown, Slate, White, Red, Black, Yellow, Violet, Rose, Aqua) to identify each fiber uniquely . For cables with more than 12 fibers, the sequence repeats with added stripes or markers (e.g., Blue with Black Stripe for fiber #13) to maintain unique identification . In loose-tube cables, the buffer tubes themselves are also color-coded to simplify locating fibers in high-count cables.

Practical Applications

• Installation and Maintenance: Outer jacket colors allow technicians to quickly identify fiber type without testing, reducing errors and installation time .
• High-Density Cables: In cables with dozens or hundreds of fibers, the combination of outer jacket color, tube color, and individual fiber color ensures accurate splicing and connection.
• Connector Identification: Fiber connectors and boots also follow color codes to indicate fiber type and polish style (UPC or APC), ensuring proper matching and performance .

Summary

The outer sheath color tape is a standardized visual cue that identifies the fiber type and application, while inner fiber and tube color coding provide detailed identification for individual strands. Using TIA-598 color codes ensures safe, efficient, and error-free fiber optic installation and maintenance across all cable types and environments .