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Fiber Optic Colour Code Chart
The TIA 598 colour code for fiber strands, buffer tubes and ribbons, with the twelve colour sequence and how to find any strand number in a cable.
The twelve colour sequence
Strands within a tube, and tubes within a cable, both follow this same order. Learn it once and you can find any strand in any cable.
Outer jacket colours
| Jacket | Fiber type |
|---|---|
| Yellow | Single mode OS1 and OS2 |
| Orange | Multimode OM1 and OM2 |
| Aqua | Multimode OM3 and OM4 |
| Lime | Multimode OM5 |
| Violet | Multimode OM4 (some makers) |
| Blue | Polarity keyed or armoured |
Reading a cable in the field
The sequence runs blue, orange, green, brown, slate, white, red, black, yellow, violet, rose, aqua. It repeats at every level: strands inside a buffer tube follow it, and the tubes themselves follow it inside the cable. A 144 strand cable is twelve tubes of twelve, and strand 27 is the third strand of the third tube.
Beyond 144 strands the tubes repeat with a tracer stripe, so the second run of twelve is blue with a stripe, orange with a stripe and so on. Ribbon cables follow the same order across the ribbon.
The jacket tells you the fiber type before you ever open it. Yellow is single mode, orange is older multimode, and aqua is the OM3 and OM4 multimode used in most modern data centres. Getting that wrong wastes a trip, because single mode and multimode equipment will not talk to each other.