EN IEC 60757:2021

Code for designation of colours

This document specifies letter codes for designation of colours and provides rules for their combination to designate colour combinations. The letter codes are intended to be applied in the technical documentation of electrical installations, electrical equipment and products, and in markings of electrical equipment and products. This basic safety publication focusing on safety essential requirements is primarily intended for use by technical committees in the preparation of safety publications in accordance with the principles laid down in IEC Guide 104 and ISO/IEC Guide 51. It is not intended for use by manufacturers or certification bodies. One of the responsibilities of a technical committee is, wherever applicable, to make use of basic safety publications in the preparation of its publications. The requirements of this basic safety publication will not apply unless specifically referred to or included in the relevant publications. This document does not specify any requirements for the encoding of colour properties, nor for their visual representation. Such requirements are under the responsibility of the different technical committees.

Kennbuchstaben für die Bezeichnung von Farben

Code de désignation de couleurs

L'IEC 60757:2021 spécifie les codes littéraux de désignation de couleurs et donne des règles régissant leur combinaison, afin de désigner les combinaisons de couleurs. Les codes littéraux sont destinés à être appliqués dans la documentation technique des installations électriques, des équipements et produits électriques, ainsi que dans les marquages des équipements et produits électriques. La présente publication fondamentale de sécurité portant sur des exigences essentielles de sécurité est avant tout destinée à être utilisée par les comités d’études dans le cadre de l’élaboration de publications de sécurité, conformément aux principes établis dans le Guide IEC 104 et le Guide lSO/lEC 51. Elle n’est pas destinée à être utilisée par les fabricants ou les organismes de certification. L’une des responsabilités d’un comité d’études consiste, le cas échéant, à utiliser les publications fondamentales de sécurité dans le cadre de l’élaboration de ses publications. Les exigences de la présente publication fondamentale de sécurité ne s’appliquent pas tant qu’il n’y a pas été fait spécifiquement référence ou qu’elles n’ont pas été incluses dans les publications concernées. Le présent document ne spécifie pas d’exigences relatives au codage des propriétés des couleurs, ni à leur représentation visuelle. De telles exigences relèvent de la responsabilité des différents comités d’études. L'IEC 60757:2021 annule et remplace la première édition parue en 1983. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: a) restriction des codes à des codes littéraux; b) suppression des anciennes notes superflues; c) ajout d’un paragraphe sur un élément utilisant différentes couleurs par alternance; d) ajout de l'0 avec des exemples de couleurs et leur codage RVB (rouge, vert, bleu) correspondant.

Koda za označevanje barv (IEC 60757:2021)

General Information

• Status: Published
• Publication Date: 05-Aug-2021
• ICS: 01.070 - Colour coding
• ICS: 29.020 - Electrical engineering in general
• Technical Committee: CLC/SR 3 - Information structures, documentation and graphical symbols
• Drafting Committee: IEC/TC 3 - IEC_TC_3
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 06-Aug-2021
• Completion Date: 06-Aug-2021
• Ref Project: SIST EN IEC 60757:2021 - Code for designation of colours (IEC 60757:2021)

Relations

• Replaces: HD 457 S1:1985 - Code for designation of colours
• Effective Date: 26-Jan-2023
• Refers: IEC 60445:2017 - Basic and safety principles for man-machine interface, marking and identification - Identification of equipment terminals, conductor terminations and conductors
• Effective Date: 10-Feb-2026
• Refers: CEN/TR 15419:2006 - Protective clothing - Guidelines for selection, use, care and maintenance of chemical protective clothing
• Effective Date: 09-Feb-2026
• Referred By: EN 4840-103:2023 - Aerospace series - Heat-shrinkable moulded shapes - Part 103: Fluoroelastomeric, temperature range -55 °C to 200 °C - Product standard
• Effective Date: 09-Feb-2026
• Referred By: EN 4708-204:2023 - Aerospace series - Sleeving, heat-shrinkable, for binding, insulation and identification - Part 204: Limited fire hazard identification sleeves - Operating Temperature range -40 °C to 105 °C - Product standard
• Effective Date: 09-Feb-2026
• Referred By: EN 60062:2016 - Marking codes for resistors and capacitors
• Effective Date: 03-Feb-2026
• Referred By: EN IEC 62677-3-101:2018 - Heat-shrinkable low and medium voltage moulded shapes - Part 3: Specification for individual materials - Sheet 101: Heat-shrinkable, polyolefin moulded shapes for low voltage applications
• Effective Date: 03-Feb-2026
• Referred By: EN 60684-3-280:2010 - Flexible insulating sleeving - Part 3: Specifications for individual types of sleeving - Sheet 280: Heat-shrinkable, polyolefin sleeving, anti-tracking
• Effective Date: 03-Feb-2026
• Referred By: EN 62329-3-101:2010 - Heat-shrinkable moulded shapes - Part 3: Specification requirements for shape dimensions, material requirements and compatibility performance - Sheet 101: Heat-shrinkable moulded shapes, polyolefin, semi-rigid, limited fire hazard, material requirements and system performance
• Effective Date: 03-Feb-2026
• Referred By: EN 61082-1:2015 - Preparation of documents used in electrotechnology - Part 1: Rules
• Effective Date: 03-Feb-2026
• Referred By: EN 62329-3-102:2010 - Heat-shrinkable moulded shapes - Part 3: Specification requirements for shape dimensions, material requirements and compatibility performance - Sheet 102: Heat-shrinkable elastomeric moulded shapes, semi-rigid, material requirements and system performance
• Effective Date: 03-Feb-2026
• Referred By: EN 60684-3-282:2010 - Flexible insulating sleeving - Part 3: Specifications for individual types of sleeving - Sheet 282: Heat-shrinkable, polyolefin sleeving - Stress control
• Effective Date: 03-Feb-2026
• Referred By: EN 62329-3-100:2010 - Heat-shrinkable moulded shapes - Part 3: Specification requirements for shape dimensions, material requirements and compatibility performance - Sheet 100: Heat-shrinkable moulded shape dimensions
• Effective Date: 03-Feb-2026
• Referred By: EN IEC 60684-3-282:2025 - Flexible insulating sleeving - Part 3: Specifications for individual types of sleeving - Sheet 282: Heat-shrinkable, polyolefin sleeving - Stress control
• Effective Date: 03-Feb-2026
• Referred By: EN IEC 61918:2018 - Industrial communication networks - Installation of communication networks in industrial premises
• Effective Date: 03-Feb-2026

Overview

EN IEC 60757:2021 - Code for Designation of Colours is an international standard developed by the European Committee for Electrotechnical Standardization (CLC) in collaboration with the International Electrotechnical Commission (IEC). This standard specifies letter codes for the designation of colours and sets out rules for combining these codes to represent colour combinations. EN IEC 60757:2021 is primarily intended for technical committees when preparing safety publications and technical documentation in the electrical engineering sector.

It serves as a basic safety publication, providing a unified approach to colour coding for electrical installations, equipment, and products. Standardized colour designations enhance clarity and safety in technical documents, wiring diagrams, and product markings, supporting consistency across international documentation practices.

Key Topics

• Letter Codes for Colours: The standard defines specific two-letter codes to represent colours (e.g., BK for black, GN for green, YE for yellow, BU for blue).
• Rules for Colour Combinations: Clear guidance is provided for how to combine letter codes to indicate:
  • Multiple colours on the same item (e.g., RDBU for red and blue)
  • Alternating colours (e.g., BU/WH for blue and white alternation)
  • Different colours on sub-items (e.g., BK+BN+GNYE+BU+GY for a cable with multiple coloured cores)
• Applicability: EN IEC 60757:2021 is meant for technical committees responsible for drafting electrical safety publications. It is not intended for direct use by manufacturers or for certification purposes, unless referenced in other relevant standards.
• Scope Limits: The standard does not regulate how colours should appear visually or their encoding (like precise RGB values); such attributes are managed by specific technical committees as needed.

Applications

Implementing EN IEC 60757:2021 improves the quality, safety, and consistency of technical documentation in the electrical sector. Key application areas include:

• Technical Documentation: Standardized colour codes simplify the preparation, reading, and interpretation of wiring diagrams, equipment manuals, and maintenance guides.
• Marking and Identification: Effective for marking cables, terminals, and equipment identifiers, aiding in installation, troubleshooting, and maintenance.
• Safety Publications: Used by technical committees to prepare safety literature with harmonized colour codes, supporting compliance with international safety principles and reducing the risk of misinterpretation.
• System Integration: Supports the unification of technical information in engineering projects that involve multiple countries or suppliers by providing a common language for colour designation.

Related Standards

EN IEC 60757:2021 is closely linked to other international and European standards that support safety and identification in electrical engineering, including:

• IEC 60445: Basic and safety principles for man-machine interfaces, identification of equipment terminals, conductor terminations, and conductors.
• IEC Guide 104 / ISO/IEC Guide 51: Principles for the preparation of safety publications, providing context and methodology that inform the application of EN IEC 60757:2021.
• Standards for Colour Coding: Additional standards addressing colour coding across various applications (referenced in technical committees’ work).

By adhering to EN IEC 60757:2021, organizations and technical committees promote safer working environments and facilitate interoperability and understanding in the electrical industry worldwide.

Keywords: EN IEC 60757:2021, code for designation of colours, electrical equipment, letter codes, colour combinations, technical documentation, colour coding, electrical safety standards, CLC, IEC, standardization.

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2021
Nadomešča:
SIST HD 457 S1:2003
Koda za označevanje barv (IEC 60757:2021)
Code for designation of colours (IEC 60757:2021)
Code zur Farbkennzeichnung (IEC 60757:2021)
Code de désignation de couleurs (IEC 60757:2021)
Ta slovenski standard je istoveten z: EN IEC 60757:2021
ICS:
01.070 Barvno kodiranje Colour coding
29.020 Elektrotehnika na splošno Electrical engineering in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60757

NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2021
ICS 29.020; 01.070 Supersedes HD 457 S1:1985 and all of its amendments
and corrigenda (if any)
English Version
Code for designation of colours
(IEC 60757:2021)
Code de désignation de couleurs Kennbuchstaben für die Bezeichnung von Farben
(IEC 60757:2021) (IEC 60757:2021)
This European Standard was approved by CENELEC on 2021-07-21. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60757:2021 E
European foreword
The text of document 3/1486(F)/FDIS, future edition 2 of IEC 60757, prepared by IEC/TC 3
“Documentation, graphical symbols and representations of technical information” was submitted to the
IEC-CENELEC parallel vote and approved by CENELEC as EN IEC 60757:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022–04–21
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024–07–21
document have to be withdrawn
This document supersedes HD 457 S1:1985 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60757:2021 was approved by CENELEC as a European
Standard without any modification.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the
relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60445 - Basic and safety principles for man-- -
machine interface, marking and
identification - Identification of equipment
terminals, conductor terminations and
conductors
IEC 60757 ®
Edition 2.0 2021-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ

Code for designation of colours

Code de désignation de couleurs

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 01.070; 29.020 ISBN 978-2-8322-9881-7

– 2 – IEC 60757:2021 © IEC 2021
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Letter codes for colours . 5
5 Application of colour designations . 6
5.1 Multiple colours on the same item . 6
5.2 Alternating colours of the same item . 6
5.3 Colours on different subitems of an item . 6
Annex A (informative) Examples of colours . 7

Table 1 – Colours and their letter code . 6
Table A.1 – Examples of the colours and their RGB encoding . 7

IEC 60757:2021 © IEC 2021 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
CODE FOR DESIGNATION OF COLOURS

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-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
mis
...