The buffer or jacket on patchcords is often color-coded to indicate the type of fiber used. The strain relief "boot" that protects the fiber from bending at a connector is color-coded to indicate the type of connection. Connectors with a plastic shell (such as SC connectors) typically use a color-coded shell. Standard color codings for jackets and boots (or connector shells) are shown below:
| Buffer/jacket color | Meaning |
|---|---|
| Orange | multi-mode optical fiber |
| Aqua | OM3 or OM4 10 gig laser-optimized 50/125 micrometer multi-mode optical fiber |
| Violet | OM4 multi-mode optical fiber (some vendors)[15] |
| Grey | outdated color code for multi-mode optical fiber |
| Yellow | single-mode optical fiber |
| Blue | Sometimes used to designate polarization-maintaining optical fiber |
| Connector Boot | Meaning | Comment | |
|---|---|---|---|
| Blue | Physical Contact (PC), 0° | mostly used for single mode fibers; some manufacturers use this for polarization-maintaining optical fiber. | |
| Green | Angle Polished (APC), 8° | ||
| Black | Physical Contact (PC), 0° | ||
| Grey, | Beige | Physical Contact (PC), 0° | multimode fiber connectors |
| White | Physical Contact (PC), 0° | ||
| Red | High optical power. Sometimes used to connect external pump lasers or Raman pumps. | ||
Remark: It is also possible that a small part of a connector is additionally colour-coded, e.g. the leaver of an E-2000 connector or a frame of an adapter. This additional colour coding indicates the correct port for a patchcord, if many patchcords are installed at one point.
