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

Standard Color Coding

For 4-core optical fiber cables, the TIA-598-C standard specifies the first four fibers in the following order: Blue, Orange, Green, Brown . This sequence is used universally for both single-mode and multimode fibers to ensure consistent identification during installation, splicing, and maintenance.

Cable Construction Context

• Loose-Tube Cables: The fibers are housed inside a colored tube (often Blue or White), and the individual fibers inside follow the Blue, Orange, Green, Brown order .
• Tight-Buffered Cables: Each fiber is individually coated and color-coded according to the same sequence, making it easier to terminate or patch in indoor environments .

Practical Notes

• The outer jacket color of the cable may indicate the fiber type: Yellow for single-mode, Orange or Aqua for multimode .
• Following this color order is critical for avoiding miswiring and ensuring proper duplex connections, as a 4-core cable often supports two duplex links or one duplex link with two backup fibers .
• For higher fiber counts, the 12-color sequence is used, but for 4-core cables, only the first four colors are relevant . By adhering to this standard, technicians can reliably identify fibers, maintain global consistency, and reduce errors during network deployment or maintenance.