Fiber Optic Color Codes

cable color

When identifying fiber optic cables and connectors, there are a few key color rules to help distinguish types and grades.

Fiber Optic Jacketing Color Code

TIA/EIA 598-C has set some guidelines for indoor jacketing coloring. For the purposes of this post, we’re only discussing non-military applications.

However: Per TIA 598-C, using different jacket colors is allowable if the cable type is identified in the print legend. Always check the print legend or contact the manufacturer, as jacket colors can be variable.

Multimode 62.5/125OrangeSlateOM1
Multimode 50/125OrangeOrangeOM2
Multimode 50/125Aquan/aOM3/4
Single Mode 9/125YellowYellowOS1/OS2

OM4 is also frequently colored violet. (The specific color is Erika Violet, which actually looks magenta.) This color choice was a convention started in Europe to cut down confusion, and it’s been adopted by many North American manufacturers, including Cleerline SSF™.

A note on OM1: OM1 is a legacy cable with a 62.5 micron core. This 62.5 micron core diameter is larger than the 50 µm core size on today’s OM2, OM3, and OM4 multimode fibers. Connectors sized for a 50/125 OM2/3/4 multimode cable will not work on a 62.5/125 OM1 multimode cable. If you are looking at an orange cable and aren’t sure what it is, always check the print legend for mentions of 62.5.

Jacket coloring is less helpful than the print legend, but if you are trying to simply determine whether you are looking at single mode or multimode fiber, it can be a good place to start.

Key Steps for Cable Identification

If you can’t identify a cable:

  1. Check the jacket color.
  2. Read the print legend
    • Look for OM1 (62.5/125), OM2 (50/125), OM3 (50/125), OM4 (50/125) or OS2 (9/125)
    • Check for a rating, such as OFNP or OFNR
    • Look for any notes about the construction (duplex, tactical, etc.)

Read the full article on cable identification.

Fiber Optic Connector Coloring

connector color

Likewise, there is some standardization for fiber optic connectors. The coloring is similar to that of the jacketing, but with some key differences. These are general guidelines and may vary by manufacturer. For example, our multimode OM3 patch cables have beige connectors that are rated for 50/125 OM3.

  • OM1 62.5/125 Multimode Connectors: Beige
  • OM2 50/125 Connectors: Black (although aqua OM3/4 connectors can also be used)
  • OM3/OM4 50/125 Connectors: Aqua, although other colors can be used.
  • OS2 Single Mode 9/125 Ultra Polish Connectors (UPC): Blue
  • OS2 Single Mode 9/125 Angled Polish Connectors (APC): Green

Key notes: multimode and single mode connectors are not interchangeable. The color coding above can help ensure that a single mode connector is never installed on a multimode cable. For more information on connector types, visit our article on fiber optic connectors.

Fiber Optic Color Codes