You can see optical fiber have different colors inside. Why ？Because fiber optic cable color coding is very important in this field.The colors don’t only apply for the application though, they also are meant to be of use in determining a cables properties.
Color code system makes it easy！Due to the small size of the fibers (approximately 250 µm in diameter), digital or other printed markings are not practical. Therefore, the most straightforward method is to color each fiber or each fiber tube individually.
The human eye can distinguish between millions of different colors, but when trying to quickly classify various colors, it is often impossible to process more than 12 colors. Therefore, all common fiber optic cable color coding systems are based on 12 different colors.
Cable jacket color code：The TIA-598C standard also makes different regulations on the color of the sheath of the indoor optical cable to distinguish different applications of the optical cable. Generally speaking, different types and different uses of optical cables also have different sheath colors. The following table shows the sheath colors of common optical cables:
| Fiber Type | Color Code | ||
| Non-military Applications | Military Applications | Suggested Print Nomenclature | |
| OM1 62.5/125µm Multimode | Orange | Slate | 62.5/125 |
| OM2 50/125µm Multimode | Orange | Orange | 50/125 |
| OM3 50/125 µm (850 nm Laser-Optimized) Multimode | Aqua | Undefined | 850 LO 50/125 |
| OM4 50/125µm (850 nm Laser-Optimized) Multimode | Aqua/Violet | Undefined | 850 LO 50/125 |
| 100/140µm Multimode | Orange | Green | 100/140 |
| OS1/OS2 Single Mode | Yellow | Yellow | SM/NZDS, SM |
| Polarization Maintaining Single Mode | Blue | Undefined | Undefined |
The color isn’t enough to fully tell the difference between the two types of fiber optic cables. In this case, the more reliable way to distinguish different optical cables is to look at the specifications and models of the optical cables.