What is the 24 fiber color code?

In the most common 2×12 configuration: tube 1 (Blue) holds fibers 1–12 in the full TIA-598-C sequence, and tube 2 (Orange) holds fibers 13–24 in the same sequence. Fiber 13 = Orange tube, Blue fiber. Fiber 24 = Orange tube, Aqua fiber.

How many tubes does a 24-count fiber cable have?

Most 24F loose-tube cables have 2 buffer tubes (2×12). Some single-tube 24F cables exist — all 24 fibers in one tube — where fibers 13–24 repeat the base color sequence with a black tracer stripe to distinguish them from fibers 1–12. The one exception is fiber 20: the Black fiber carries a WHITE tracer, because a black stripe on a black fiber would be unreadable.

What color is fiber 17 in a 24-count cable?

In a 2×12 cable, fiber 17 is in tube 2 (Orange tube). Its position within the tube: ((17-1) mod 12)+1 = 5 → Slate. So fiber 17 = Orange tube, Slate fiber.

Why is a green fiber sometimes fiber 3 and sometimes fiber 15?

Because the colors run 1–12 and then start over. Green is not a fiber number on its own: green in the Blue tube is fiber 3, green in the Orange tube is fiber 15. The tube color is what separates them, so never read the fiber color alone. Missing the tube puts you off by twelve.

24 fiber color code

A 24-count fiber cable ships in two shapes Fiber Optic Color Code Lookup covers: two buffer tubes of 12 fibers each, or one larger tube of 24 where the second dozen carries tracers. The color order below covers the most common 2×12 configuration.

A 24F cable is essentially two of the 12-fiber color code base stacked into one sheath, and the same TIA-598-C logic scales up through 48F to the 96-fiber color code 8-tube build.

The part that trips people up: green is not a fiber number

The colors do not run 1 through 24. They run 1 through 12, then start over. So a green fiber could be fiber 3 or fiber 15 — the tube color is the only thing separating them. Green in the Blue tube is 3. Green in the Orange tube is 15. Miss the tube and you are off by twelve, which on a live network is the difference between the right customer and an outage two streets over.

You do not need to memorize 24 positions. You need the 12-color order and the two tube colors; the rest is counting. Fiber 20 sits in the Orange tube (that is 13–24) and it is the 8th color in the sequence — Black. Orange tube, black fiber, fiber 20. No math beyond counting to eight.

Tube colors (2×12 configuration)

For two buffer tubes, tubes follow the first two TIA-598-C positions:

1. Blue
2. Orange

Fiber colors within each tube

Inside each tube, fibers run the full TIA-598-C 12-color sequence:

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

Fiber-number → (tube, color) lookup

Fiber #	Tube	Tube color	Fiber color
1	1	Blue	Blue
2	1	Blue	Orange
3	1	Blue	Green
4	1	Blue	Brown
5	1	Blue	Slate
6	1	Blue	White
7	1	Blue	Red
8	1	Blue	Black
9	1	Blue	Yellow
10	1	Blue	Violet
11	1	Blue	Rose
12	1	Blue	Aqua
13	2	Orange	Blue
14	2	Orange	Orange
15	2	Orange	Green
16	2	Orange	Brown
17	2	Orange	Slate
18	2	Orange	White
19	2	Orange	Red
20	2	Orange	Black
21	2	Orange	Yellow
22	2	Orange	Violet
23	2	Orange	Rose
24	2	Orange	Aqua

1×24 with tracers

Some manufacturers (notably Corning ALTOS in certain product lines) ship 24-fiber cables with a single large tube holding all 24 fibers. Fibers 13–24 repeat the base 12-color sequence but carry an identifying tracer stripe — black. So fiber 13 = Blue with black tracer, fiber 14 = Orange with black tracer, and so on.

The one exception is fiber 20. Fiber 8 is Black, so its repeat at position 20 cannot take a black stripe and stay readable — it carries a white tracer instead. Every chart that states the rule as “black tracer on the second dozen” is wrong on exactly one fiber, and it is the one you are least able to read in a dark closure. The app returns F20-BLK/WHT for it.

Ribbon builds

Ribbon 24F pairs two 12-fiber ribbons — the 12-fiber ribbon is the unit TIA-598 builds on, the same one behind the 96-fiber 8-ribbon and 144-fiber 12-ribbon stacks. Ribbons are identified by position in the stack and by edge print rather than by tube color, but the colors along each ribbon are the same TIA-598-C order.

Worth knowing before you plan trays: the app's database ships no 24F ribbon configuration. Its 24-count coverage is the 2×12 loose-tube builds and the 1×24 central tube above. Ribbon entries exist at higher counts, where ribbon construction is far more common.