IEC TR 63194:2019

Guidance on colour coding of optical fibre cables

IEC TR 63194:2019 which is a Technical Report, examines the need for and intent of colour coding of optical fibre cables. Further, this document lists the major colour codes in various regions throughout the world. Noting that decades of discussion of a universal recommended colour coding scheme has failed to bring about an agreement, this document does not intend to promote any listed colour code above any other. This document includes regional information on the colour coding of units when different from the fibre code, and of jackets to convey information about the types of fibres within, or the types of performance expected. It also includes information on colours beyond the basic 12 set out in IEC 60304. This document is not a normative document, but, rather, a guide to the subject of colour coding of cables.
Keywords: colour coding of optical fibre cables

General Information

• Status: Published
• Publication Date: 29-Jan-2019
• ICS: 33.180.10 - Fibres and cables
• Technical Committee: SC 86A - Fibres and cables
• Current Stage: PPUB - Publication issued
• Start Date: 30-Jan-2019
• Completion Date: 06-Mar-2019

Overview

IEC TR 63194:2019 - Guidance on colour coding of optical fibre cables is a Technical Report from the IEC that reviews the need, intent and practice of colour coding for optical fibre cables. This non‑normative guide catalogs major regional colour codes, documents historic IEC approaches (including references to IEC 60794‑2), and explains how colours are used for individual fibres, units/groups and outer jackets. The report explicitly does not promote one regional scheme over another and includes guidance on colours beyond the basic 12 set out in IEC 60304.

Key Topics

• Purpose and rationale for colour coding of optical fibre cables and common operational objectives (identification, maintenance, safety).
• Fibre colour coding: intent, historic IEC schemes, and extensions (e.g., coding for fibres 13–16 and high‑count arrangements).
• Unit and group coding: identification of tubes, fibre units and grouping methods used in composite and loose‑tube cables.
• Jacket colour coding: conventions to convey fibre types, expected performance, or application (including striping techniques).
• Measurement and specification of colour: preparation of specimens, methods to specify colour (examples include Munsell and RaL centroid values), and guidance on consistent colour measurement.
• Regional annexes: informative examples from Germany, North America, Sweden, Switzerland, China, Japan and Brazil with tables and figures illustrating local schemes and counting codes.
• Non‑normative guidance: clear statement that the document is for information and reference, not a mandatory standard.

Applications

IEC TR 63194 is practical for organizations and activities that require clear optical fibre identification:

• Cable manufacturers - selecting or documenting colour schemes for production and labeling.
• Network designers and planners - specifying cable identification schemes compatible with regional practices.
• Installers and field technicians - interpreting jacket/ unit/ fibre colours for splicing, testing and maintenance.
• Test laboratories and quality control - using the measurement guidance to verify colour consistency.
• Procurement and compliance teams - comparing supplier documentation to regional or project colour conventions.
• Standards committees and educators - referencing comparative regional schemes when proposing harmonized practices.

Related standards

• IEC 60304 - basic 12 colour set reference.
• IEC 60794‑2 - historic/follow‑up fibre and tube coding practices referenced in the report.
• IEC TR 63194 is published by IEC TC 86 (Fibre optics) and serves as a state‑of‑the‑art informational resource for the colour coding of optical fibre cables.

Keywords: colour coding of optical fibre cables, IEC TR 63194, fibre colour coding, jacket colour coding, fibre identification.

Standards Content (Sample)

IEC TR 63194 ®
Edition 1.0 2019-01
TECHNICAL
REPORT
colour
inside
Guidance on colour coding of optical fibre cables

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IEC TR 63194 ®
Edition 1.0 2019-01
TECHNICAL
REPORT
colour
inside
Guidance on colour coding of optical fibre cables

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.180.10 ISBN 978-2-8322-6517-8

– 2 – IEC TR 63194:2019 © IEC 2019
CONTENTS
CONTENTS . 2
FOREWORD . 5
INTRODUCTION . 7
0.1 General . 7
0.2 Background in other documents . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Rationale . 8
5 Fibre colour coding . 9
5.1 Intent . 9
5.2 Historic IEC 60794-2 colour code (for guidance) . 9
5.3 Colour coding for fibres 13 through 16 . 10
5.4 Other coding schemes . 10
6 Unit and group coding. 10
6.1 Unit coding . 10
6.2 Group coding . 11
6.3 Coding of tubes in composite cables, IEC 60794-2 . 11
6.4 Other coding schemes . 11
7 Jacket colour coding . 11
7.1 General . 11
7.2 IEC 60794-2 jacket colour code . 12
7.2.1 Historic IEC jacket colour code . 12
7.2.2 Current IEC jacket colour code . 12
7.3 Jacket coding by striping . 13
7.4 Other jacket colour code . 13
8 Guidance on the measurement of colour . 13
8.1 General . 13
8.2 Preparation of specimens for colour measurement . 13
8.3 Specification of colour . 13
Annex A (informative) German colour code . 14
A.1 Fibre colour coding . 14
A.2 German counting code for tubes stranded in a layer . 14
A.3 Jacket colour coding . 15
Annex B (informative) North-American colour code . 16
B.1 Fibre colour coding . 16
B.2 Unit coding . 19
B.3 Jacket colour coding . 19
Annex C (informative) Swedish colour code S12 . 21
C.1 Fibre colour coding S12 . 21
C.2 Unit coding scheme S12 . 21
C.2.1 General . 21
C.2.2 Sequence for individual fibres within a tube/fibre-unit/bundle and for
individual tubes/fibre-units/yarns, etc. . 21
C.2.3 Sequence for tubes stranded around a central part . 21
C.3 Jacket colour coding . 22

Annex D (informative) Swiss colour code . 23
D.1 Fibre colour coding . 23
D.2 Unit coding . 24
D.3 Jacket colour coding . 24
Annex E (informative) Chinese colour code . 26
E.1 Fibre colour coding . 26
E.2 Unit coding . 27
E.3 Jacket colour coding . 29
Annex F (informative) Japanese colour code . 30
F.1 Fibre colour coding . 30
F.2 Unit coding by identification strip . 31
F.3 Jacket colour coding of multi-fibre indoor cable . 32
Annex G (informative) Brazilian colour code . 33
G.1 Fibre colour coding . 33
G.2 Unit colour coding of buffer tubes . 33
G.3 Jacket colour coding . 33
Bibliography . 34

Figure C.1 – Sequence of tubes by position . 22
Figure D.1 – Example of an 18-way stranded loose tube cable . 24
Figure D.2 – Example of an outdoor cable, black with orange stripes . 25
Figure E.1 – Sequence of tubes by position . 27
Figure E.2 – Example of a 24-tube stranded loose tube cable . 28
Figure E.3 – Example of T Mark Colour Code . 29
Figure F.1 – Colour coding scheme based on optical fibre ribbon. 30
Figure F.2 – Identification strip to bundle several optical fibre ribbons . 31
Figure F.3 – Overview of high-count indoor cable . 32

Table 1 – Colour coding sequence for individual fibres or buffers . 10
Table 2 – Colours for individual fibres, buffers, or other elements 13 through 16. 10
Table 3 – Colour coding scheme for tubes in hybrid or composite cables . 11
Table 4 – Colour coding of cable outer sheaths . 12
Table 5 – Colour coding of cable outer sheaths by fibre type . 12
Table 6 – Example of centroid values for base colours in Munsell and R*a*L systems . 13
Table A.1 – Colour coding sequence for individual fibres . 14
Table A.2 – Counting code and colours from the German specification . 15
Table B.1 – Individual fibre, unit, and group identification for up to 12 elements in a set . 16
Table B.2 - Individual fiber, unit, and group identification for up to 16 elements in a set . 18
Table B.3 – Sample identification markings . 19
Table B.4 – North American preferred coding scheme for indoor cable jackets . 20
Table C.1 – Sequence for individual fibres within a tube/fibre-unit/bundle and for
individual tubes/fibre-units/yarns, etc. . 21
Table D.1 – Colour coding sequence for individual fibres or buffers in mini-breakout
cables . 23
Table D.2 – Colour coding for buffered fibres in simplex, duplex or breakout cables . 24

– 4 – IEC TR 63194:2019 © IEC 2019
Table D.3 – Colour coding and sequence for loose tubes stranded around a central part . 24
Table D.4 – Colour coding for sub-cables and outer sheaths of indoor cables . 25
Table D.5 – Colour for outer sheaths of outdoor cables . 25
Table E.1 – Colour coding for individual fibres . 26
Table E.2 – Colour coding for fibre counts up to 24 . 26
Table E.3 – Colour coding for loose tubes up to 12 . 27
Table E.4 – Colour coding for loose tubes up to 24 . 28
Table E.5 – Chinese colour coding scheme for indoor cable jackets. 29
Table F.1 – Japanese colour coding for underground optical cable . 30
Table F.2 – Japanese colour coding for aerial optical cable . 31
Table F.3 – Colour coding of identification strip . 31
Table F.4 – Jacket colour coding in high-count indoor cable . 32
Table G.1 – Brazilian colour coding for fibre identification . 33

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
GUIDANCE ON COLOUR CODING OF OPTICAL FIBRE CABLES

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all
national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-
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The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a Technical Report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC TR 63194, which is a Technical Report, has been prepared by subcommittee 86A: Fibres
and cables, of IEC technical committee 86: Fibre optics.
The text of this Technical Report is based on the following documents:
Draft TR Report on voting
86A/1870/DTR 86A/1891A/RVDTR
Full information on the voting for the approval of this Technical Report can be found in the report
on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

– 6 – IEC TR 63194:2019 © IEC 2019
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INTRODUCTION
0.1 General
Colour coding of fibres is a useful method to uniquely identify fibres within a cable. For most
fibre system architectures, such identification is considered essential.
A number of schemes for fibre identification have evolved in various regions. Attempts to unify
the schemes have not yet been successful, as they are embedded in the system architecture.
Jacket colour coding is frequently used for a variety of reasons – most commonly in indoor
cables.
Colour coding of both fibres and jackets has been addressed in IEC 60794-2 [5] [6] and in
IEC 60794-3-11. The intent of this document is to collect that and other relevant information for
application to all cable types defined by IEC 60794 (all parts).
0.2 Background in other documents
IEC 60304 [1] defines the 12 colours currently identified for fibre identification, but does not
specify which colour is for which fibre number. IEC 60794-2:2002 [5] does define a colour code,
but this has been determined to have been construed as not representing any existing major
colour code; furthermore, it was never adopted by any region. Further discussion of both
documents is included in the text that follows.
IEC 60794-1-1 [4] contains specific language on the intent of colour coding, and notes that it is
"as agreed". This document expands on that intent, offering several specific examples that exist
in the various regions. Where the information is available, this document notes the regional
specifications from which these examples are taken.

______________
Numbers in square brackets refer to the Bibliography.

– 8 – IEC TR 63194:2019 © IEC 2019
GUIDANCE ON COLOUR CODING OF OPTICAL FIBRE CABLES

1 Scope
This document examines the need for and intent of colour coding of optical fibre cables. Further,
this document lists the major colour codes in various regions throughout the world. Noting that
decades of discussion of a universal recommended colour coding scheme has failed to bring
about an agreement, this document does not intend to promote any listed colour code above any
other.
This document includes regional information on the colour coding of units when different from the
fibre code, and of jackets to convey information about the types of fibres within, or the types of
performance expected. It also includes information on colours beyond the basic 12 set out in
IEC 60304.
This document is not a normative document, but, rather, a guide to the subject of colour coding
of cables.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 Rationale
The need to uniquely identify a particular fibre within a cable is a common and rational
requirement for cable standards. The determination of which fibre is which – without having to
resort to "ringing it out" – is a key criteria in cable system management. A definition of an agreed
cable colour coding scheme has been discussed in past years. But it has not been possible to
reach agreement within the IEC because several embedded regional coding schemes exist that
are part and parcel of the fibre system architecture.
The regional coding schemes are presented in Annexes A to G, as follows:
• Annex A: Germany;
• Annex B: North America;
• Annex C: Sweden;
• Annex D: Switzerland;
• Annex E: China;
• Annex F: Japan;
• Annex G: Brazil.
The rationale of a colour coding scheme is that each fibre within a cable be uniquely identified.
This concept requires that each fibre in a unit be identified by colour or position or both, and that
each unit also be identified – again, by colour or position or both. The combination of the two will
uniquely identify any particular fibre within a cable. The scheme for the fibre and for the unit may
or may not be the same.
Note that IEC 60304 defines the 12 colours for fibre identification, but does not specify which
colour is for which fibre number. Also note that IEC 60794-3-11:2010 [7], 6.1.3.1, lists the 12
colours, but specifically leaves the coding to being "as agreed".
The only definition of a colour code in the IEC 60794 system to date appears in
IEC 60794-2:2017, 5.13. IEC 60794-2:2002, and earlier, contained a colour code for fibre
identification; edition 4.0 (2017) does not contain that code. That code has been anecdotally
described as having been "made up" to specifically not conform to any existing code, in hopes
that it might become an agreed default. That agreement never occurred, therefore, it was
dropped from edition 4.0. The stated colour codes stated in IEC 60794-2:2017 [6] are for fibre,
buffered fibre, ribbons, unit, ruggedized fibre elements and jacket colours, based on fibre type.
The current work to restructure the IEC 60794-1 series – especially the revision of
IEC 60794-1-1 – would suggest that the colour code should be a basic criterion addressed in the
general specification.
Contemporary proposals with regards to the latest edition of IEC 60794-1-1 seek to move these
criteria to IEC 60794-1-1 [4] and to this document, presuming some future revision of IEC 60794-
2:2017. They present the necessary changes to IEC 60794-1-1 to standardize the "as agreed"
approach and refer to this document for details. In view of current and future revisions, it may be
that IEC 60794-1-1 will be normative regarding these requirements.
In addition, a jacket, sub-cable jackets, tube, or buffer colour may be used to identify the type of
fibre within the cable. This type of coding may or may not conflict with the unique identification
rationale of the coding scheme, depending on the cable type.
5 Fibre colour coding
5.1 Intent
The intent of fibre colour coding is to uniquely identify each fibre in a cable. Schemes meeting
this intent require either positive identification (such as a colour) or default identification (such as
positional coding).
Fibre colours are generally defined by up to 12 colours, as per IEC 60304. Beyond 12 colours,
schemes such as dashes, hachures, or multi-colours have been used. For special applications,
such as hermetically-sealed fibres, additional colours have been used. Subclause 5.3 proposes
colours 13 through 16, based on these applications.
Fibre coding schemes for cables with larger numbers of fibres will frequently require similar
identification of the units in order to achieve unique fibre-level identification. Unit coding is
addressed in Clause 6.
Colour coding of buffered fibres generally follows the scheme for fibres.
5.2 Historic IEC 60794-2 colour code (for guidance)
Table 1 shows the colour code published in IEC 60794-2:2002, 3.13. While there is no known
use of this scheme, it is presented, here, for completeness.
NOTE It is said, anecdotally, that this code was created to be unique and not align with any major known code in the
hope that it might be adopted without prejudice. This has proven not to have been successful.

– 10 – IEC TR 63194:2019 © IEC 2019
Table 1 – Colour coding sequence for individual fibres or buffers
Fibre number Colour
1 Blue
2 Yellow
3 Red
4 White
5 Green
6 Violet
7 Orange
8 Grey
9 Turquoise
10 Black
11 Brown
12 Pink
For fibre counts above 12, additional groups of 12 fibres should be identified by
combining the above sequence with an added identification (for example, ring
marking, dashed mark, or tracer.

5.3 Colour coding for fibres 13 through 16
For colour coding of fibres or other elements in units defined beyond the basic 12 of IEC 60304,
the colours of Table 2 can be used.
Table 2 – Colours for individual fibres, buffers, or other elements 13 through 16
Colour
Olive
Magenta
Tan
Lime
5.4 Other coding schemes
For future study.
6 Unit and group coding
6.1 Unit coding
Units are primary groupings of individual fibres. Examples of such units include buffer tube,
bundles, ribbons and the like. Coding of units may be required to achieve unique fibre
identification as per Clause 5. Unit coding follows the intent of the regional coding scheme, as in
Clause 5.
Coding may be accomplished by colouring the units, buffer tubes, threads, etc. Coding may be
accomplished using printed identifications, as on ribbons or tubes. Coding may use a positional
identification scheme, as in slotted cores.

6.2 Group coding
Groups are collections of units. Examples of groups include, but are not limited to: buffer tubes
which contain ribbons, bundled fibres or the like; ribbons which are assembled from two or more
smaller ribbons; and bundles of fibre or ribbon assembled from multiple smaller bundles. Coding
of groups may be required to achieve unique fibre identification per Clause 5. Group coding shall
follow the intent of the regional coding scheme, as in Clause 5 and in Annexes A to G.
Coding may be accomplished by colouring the groups, buffer tubes, threads, etc. Coding may be
accomplished using printed identifications, as on ribbons or tubes. Coding may use a positional
identification scheme, as in slotted core.
6.3 Coding of tubes in composite cables, IEC 60794-2
Composite cables comprising several types of fibres may have the tubes or other units
containing the fibres coded as to the fibre type. Table 3 defines the tube colours as specified in
IEC 60794-2. Such coding is not defined in other regional schemes at this time.
Table
...