The standard color sequence for a 4-core optical fiber cable is Blue, Orange, Green, and Brown according to TIA-598-C.

Fiber Color Coding

A 4-core optical fiber cable contains four individual fibers within a single protective jacket, typically used for two duplex links or one duplex link with two backup fibers . The TIA-598-C standard specifies the color sequence for the first four fibers as:

1. Blue
2. Orange
3. Green
4. Brown This sequence ensures consistent identification for splicing, termination, and troubleshooting . In loose tube cables, the tube holding the fibers may be colored (commonly Blue or White), while the fibers inside follow the Blue/Orange/Green/Brown order .

Single-Mode vs. Multimode Considerations

• Single-mode (SM) fibers: Typically have a yellow jacket for indoor use or black for outdoor, with a 9µm core suitable for long-distance transmission .
• Multimode (MM) fibers: Usually have orange, aqua, or violet jackets, with a 50µm core for short-distance applications like data centers or CCTV under 300 meters .

Installation Tips

• Maintain minimum bend radius to prevent fiber damage .
• Avoid pulling on connectors; use proper pulling grips .
• For outdoor or armored cables, strength members like steel wire or Kevlar protect against stretching .
• When laying loops, use a figure-8 pattern to prevent twisting and kinking .

Summary

For a 4-core optical fiber cable, always follow the Blue, Orange, Green, Brown sequence for fiber identification. This standardization ensures proper connectivity, reduces errors during splicing, and aligns with international TIA-598-C guidelines . Proper handling and installation techniques further protect the fibers and maintain signal integrity.