Field Tool
Fiber Color Locator
Find the tube color and fiber color for a fiber number, or the fiber number for a tube and fiber color.
FAHMY Fiber Color: fiber 137 (12 fibers per tube) = tube 12 Aqua, fiber 5 Slate. Tube 12 holds fibers 133-144.
Good: Base 12-color sequence (TIA-598)Fiber 137 is the slate fiber in the aqua tube.
Tube 12 Holds Fibers 133–144
- 1Blue
- 2Orange
- 3Green
- 4Brown
- 5Slate (this fiber)
- 6White
- 7Red
- 8Black
- 9Yellow
- 10Violet
- 11Rose
- 12Aqua
The 12-Color Sequence
- 1 Blue (BL)
- 2 Orange (OR)
- 3 Green (GR)
- 4 Brown (BR)
- 5 Slate (SL)
- 6 White (WH)
- 7 Red (RD)
- 8 Black (BK)
- 9 Yellow (YL)
- 10 Violet (VI)
- 11 Rose (RS)
- 12 Aqua (AQ)
Tubes and fibers follow the same sequence. Swatches are screen approximations; read the color on the cable, not the screen.
Show the Math
tube = ⌈ n ÷ k ⌉ position = n − (tube − 1) × k
n is the fiber number and k is the number of fibers per tube (6, 12 or 24). Fiber 137 in a 12-fiber-per-tube cable sits in tube 12, position 5: the slate fiber in the aqua tube.
Identification Rules
- Positions 1–12: blue, orange, green, brown, slate, white, red, black, yellow, violet, rose, aqua. TIA-598 color sequence
- Positions 13–48 repeat the sequence with a tracer, and the tracer scheme varies. The tool shows one common scheme and grades every position above 12 as "marking varies": 13–48 marking
- 13–24: the base color with a black tracer. The repeated black gets a white or a yellow tracer, depending on the cable.
- 25–36: shown as a double black tracer (black gets double white). Some cables use a single red tracer (red gets yellow) or an orange tracer instead.
- 37–48: shown as a green tracer (green gets orange). Some cables use a triple black tracer (black gets triple white) instead.
- ANSI/TIA-598-D-1 adds olive, magenta, tan and lime for positions 13–16, so a cable may use those solid colors instead of a tracer.
- Above 48 there is no standard color: marking varies by manufacturer.
- In 24-fiber tubes, some manufacturers make fiber 20 a natural (uncolored) fiber with a black tracer.
Assumptions
- Fibers are numbered in tube order, starting at tube 1, position 1.
- The cable follows TIA-598. Confirm the marking on the cable spec sheet before you cut.
Source
FAHMY tools give planning estimates. The owner's specifications, the authority having jurisdiction and the manufacturer's data govern every job. Values marked "Planning assumption", "Planning default", "Typical maximum", "Rule of thumb" or "Example" are editable starting points, not requirements; "Per owner spec" fields take the owner's value.