FOA Guide

Fiber Optic Cable And Connector Color Codes

fiber optic color codes

Color codes are used in fiber optics to identify fibers, cables and connectors. In the photos above, on the left is a 1728 fiber cable with color coded buffer tubes, in the center are (from the top) singlemode zipcord cable used for patchcords with each fiber color coded, and on the right, a yellow SM cable with a blue connector indicating a PC connector, an orange cable with beige connector indicating 62.5/125 multimode fiber and an acqua cable and connector that identifies laser-optimized 50/125 fiber.

When a tech opens a fiber optic cable to prepare it for splicing, they will find a colorful bundle of buffer tubes as on this armored cable.

color codes-cable

The colors of the buffer tubes and likewise the fibers in the tubes provide the identification the tech needs to complete the splicing of the fibers as the cable plant was designed.

Color codes are especially important when making connections by splicing. Here is a splice tray in a pedestal where fibers from a 24 fiber OSP cable with 250 micron buffer fiber are spliced to pigtails with 900 micron buffer fibers. You can see the colors and if you look closely, you will see the matching colors of the spliced fibers.

color codes in splice tray

Here is another example with an OSP splice closure where a 432 fiber cable is broken out to two separate cables.

color codes in fiber optic closure

Each splice tray has 72 splices so the arrangement of the colored buffer tubes and the colored fibers is used to keep all the connections correct.

Splicing ribbon cable is easier, since the ribbons are arranged in the standard way shown below so one must only match up the ribbons.

ribbon splices

Here's how the spliced ribbons look:

ribbon splice

Patchcords used with patch panels can easily get mixed up. Standards use color codes for fiber and connector types to make it easy to find the right patchcord.

connector color codes

Color codes make it easy to identify these patchcords which all have SC connectors: aqua cable and connector indicate  50/125 laser optimized fiber on the cable to the left. In the center, orange cable means multimode fiber and the beige connector indicates 62.5/125 fiber. On the right, the yellow patchcord indicates singlemode fiber and the blue connector means it is a regular PC polished connector, If it were an APC connector, it would be green.

Perhaps nothing is more complex in fiber optics than maintaining polarity of fibers when using multi-fiber array connectors of the MPO type. In the TIA-568 standard that covers fiber polarity, MPO polarity takes almost 40 pages to explain. Here is a typical MPO cable:

MPO cable color codes

Breakout cables for MPO cable plants need color codes to keep track of the individual connector fibers.

MPO color breakout codes

The beige connectors indicate this is 62.5/125 fibers. Colot codes on the 900 micron tight buffer fiber identifies fibers 1-12.


Standards For Color Codes

There is a color code standard in TIA, TIA-598 that addresses fiber optic color codes, which most manufacturers adopt and reference, although there are many exceptions based on customer requirements or preferences. Here is what TIA-598 recommends:


Cable Jacket Colors

Colored outer jackets and/or print may be used on Premises Distribution Cable, Premises Interconnect Cable or Interconnect Cord, or Premises Breakout Cable to identify the classification and fiber sizes of the fiber. (Outdoor cables are generally black for protection against UV light and markings are printed on the cable.)

When colored jackets are used to identify the type of fiber in cable containing only one fiber type, the colors shall be as indicated in Table 3. Other colors may be used providing that the print on the outer jacket identifies fiber classifications. Such colors should be as agreed upon between manufacturer and user.

Unless otherwise specified, the outer jacket of premises cable containing more than one fiber type shall use a printed legend to identify the quantities and types of fibers within the cable. Table 3 shows the preferred nomenclature for the various fiber types, for example "12 Fiber, 8 x 50/125, 4 x SM." Some manufacturers use black as the jacket color for hybrid or composite cables.

When the print on the outer jacket of premises cable is used to identify the types and classifications of the fiber, the nomenclature of Table 3 is preferred for the various fiber types. Distinctive print characters for other fiber types may be considered for addition to Table 3 at some future date.

 Fiber Type  Color Code
.  Non-military Applications(3)  Military Applications  Suggested Print Nomenclature
  Multimode (50/125)  (OM2)  Orange  Orange  OM2, 50/125
 Multimode (50/125) (850 nm Laser-optimized)  (OM3, OM4)  Aqua  Undefined  OM3 or OM4,  850 LO 50 /125
 Multimode (50/125) (850 nm Laser-optimized)  (OM5)  Lime Green  Undefined   OM5
 Multimode (62.5/125) (OM1)  Orange  Slate  OM1, 62.5/125
 Multimode (100/140)  Orange  Green  100/140
 Single-mode (OS1, OS1a, OS2)  Yellow  Yellow  OS1, OS1a, OS2, SM/NZDS, SM
 Polarization Maintaining Single-mode  Blue  Undefined  Undefined (2)

 NOTES:
1) Natural jackets with colored tracers may be used instead of solid-color jackets.
2) Because of the limited number of applications for these fibers, print nomenclature are to be agreed upon between manufacturer and enduser
3) Other colors may be used providing that the print on the outer
jacket identifies fiber classifications per subclause 4.3.3.
4) For some Premises Cable functional types (e.g., plenum cables), colored jacket material may not be available. Distinctive jacket colors for other fiber types may be considered for addition to Table 3 at some future date.


Users have been installing hybrid (MM+SM) cables in the backbone for years. With the premises fiber optic cabling now including several varieties of 50/125 fiber, 62.5/125 and singlemode fibers, managing the cable plant is more difficult. We have already seen instances of users and installers being confused and getting bad test results, as well as having problems with networks operating when connected over the wrong fiber type. Connector color codes may be used to identify fiber type also. If unsure about the fiber, core size can be determined by examining the connector ferrule with a fiber optic inspection microscope while illuminating the fiber with a white light (flashlight).


Connector Color Codes:
Since the earliest days of fiber optics, orange, black or gray was multimode and yellow singlemode. However, the advent of metallic connectors like the FC and ST made connector color coding difficult, so colored strain relief boots were often used.
Fiber type
Connector Body
Strain Relief/
Mating Adapter
62.5/125
Beige
Beige
50/125 OM2
Black
Black
50/125 laser optimized (OM3, OM4)
Aqua
Aqua
OM5 wideband fiber
Lime
Lime
Singlemode
Blue
Blue
Singlemode APC
Green
Green


Fiber Color Codes
Inside the cable or inside each tube in a loose tube cable, individual fibers will be color coded for identification. Fibers follow the convention created for telephone wires except fibers are identified individually, not in pairs.

Buffer tubes follow the same color sequence up to 12 tubes, then tubes 13-24 will repeat the colors with a black stripe (black will have a yellow stripe), tubes 25-36 will follow the same color with an orange stripe, 37-48 use a green stripe, following the same color code sequence for the stripe. Tubes containing more than 12 fibers will use binder tape to separate fibers into groups. Ribbon cables follow this color sequence also.

For splicing, like color fibers are generally spliced to ensure continuity of color codes throughout a cable run.


Fiber Number Color
1 Blue
2 Orange
3 Green
4 Brown
5 Slate
6 White
7 Red
8 Black
9 Yellow
10 Violet
11 Rose
12 Aqua


There is a publicly available document that defines the twelve TIA/EIA colors for fiber conductors: http://munsell.com/color-blog/color-codingchart-wire-color-coding/


Note: Fibers 13-16 are specified for 16 fiber MPO connectors as follows: 13: Olive, 14: Magenta, 15: Tan, 16: Lime.

Fiber Number Color
1 Blue
2 Orange
3 Green
4 Brown
5 Slate
6 White
7 Red
8 Black
9 Yellow
10 Violet
11 Rose
12 Aqua
13
Olive
14
Magenta
15
Tan
16
Lime

There is a publicly available document that defines the twelve TIA/EIA colors for fiber conductors: http://munsell.com/color-blog/color-codingchart-wire-color-coding/




 


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