Indoor fiber optic cable color

Indoor fiber optic cables are color-coded by type: OM1/OM2 are orange, OM3 is aqua, OM4 can be aqua or violet, OM5 is lime green, and single-mode fibers are yellow.

Multimode Fiber Colors

• OM1 and OM2: Typically have an orange outer jacket, though OM1 and OM2 are older standards and mostly found in legacy networks .
• OM3: Uses an aqua jacket, optimized for laser transmission and common in modern multimode installations .
• OM4: Can be aqua like OM3, but some manufacturers use violet (Erika violet) to distinguish it in high-density setups .
• OM5: Identified by a lime green jacket, designed for shortwave division multiplexing (SWDM) to support higher data rates over multimode fibers .

Single-Mode Fiber Colors

• OS1 and OS2: Standard single-mode fibers have a yellow outer jacket, suitable for long-distance, high-speed transmission using laser light sources .

Additional Notes

• The outer jacket color is the primary visual indicator of fiber type, but printed labels on the cable often provide exact specifications.
• Inside multi-fiber cables, individual fibers are also color-coded in a 12-color repeating sequence to identify each strand for splicing and termination .
• Connector colors further indicate polish type: blue for UPC (flat polish) and green for APC (angled polish), which is critical for proper mating and performance . By following these standardized color codes, technicians can quickly identify fiber types, reduce installation errors, and maintain network reliability in indoor environments .