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

Overview

EN IEC 60757:2021 is a European standard established by CLC that specifies a standardized code for the designation of colours using letter codes. This standard defines clear rules for combining letter codes to identify single and multiple colour designations, primarily for use in technical documentation of electrical installations, equipment, and products. As a basic safety publication, it focuses on essential safety requirements and aids technical committees in preparing safety-related documents aligned with IEC Guide 104 and ISO/IEC Guide 51 principles.

This standard does not apply to manufacturers or certification bodies directly, nor does it define colour property encoding or visual representation requirements. Instead, it serves as a reference for technical committees to facilitate consistent and unambiguous communication regarding colour coding in electrical engineering.

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Key Topics

• Letter Codes for Colours
  EN IEC 60757:2021 assigns specific two-letter codes to fundamental colours used in electrical applications. These include codes such as:

  • Black (BK)
  • Brown (BN)
  • Red (RD)
  • Orange (OG)
  • Green (GN)
  • Yellow (YE)
  • Blue (BU)
  • Violet (VT)
  • Grey (GY)
  • White (WH)
  • Pink (PK)
  • Gold (GD)
  • Turquoise (TQ)
  • Silver (SR)

• Combination Rules for Colour Designations

  • Multiple Colours on One Item: Concatenate codes in the sequence defined by the standard (e.g., red and blue = RDBU).
  • Alternating Colours: Separate alternating colours with a “/” (solidus). Example: blue and white alternating = BU/WH.
  • Different Colours on Subitems: Separate by “+” when describing colours of different subcomponents (e.g., BK+BN+GNYE+BU+GY for cables with multiple coloured cores).

• Restrictions on Colour Use
  The green-and-yellow combination (GNYE) is limited to specific uses as per IEC 60445 and must not be used in other colour combinations.

• Colour Examples with RGB Codes
  Annex A provides typical RGB values for each colour to ensure unambiguous identification in documentation without prescribing strict colour matching.

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Applications

EN IEC 60757:2021 is crucial for consistent and clear colour coding in electrical engineering documentation and equipment marking, supporting:

• Electrical Installations: Clear, standardized colour codes improve identification and reduce errors during installation and maintenance.
• Equipment Markings: Standardized letter codes help avoid ambiguity in safety-critical markings on electrical devices.
• Technical Documentation: Enables uniform reference to colours across manuals, schematics, and safety publications.
• Safety Publications: Supports compliance with essential safety requirements through clear colour communication.

This standard benefits technical committees drafting safety standards, ensuring uniformity and safety in the international electrotechnical sector.

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Related Standards

• IEC 60445 – Basic and safety principles for man-machine interface, marking and identification: covers identification of terminals, conductor terminations, and conductors, complementing the colour designation rules in EN IEC 60757:2021.
• IEC Guide 104 – Preparation of safety publications: provides principles governing safety-related standards development within the IEC.
• ISO/IEC Guide 51 – Safety aspects guidelines: provides a framework for specifying safety requirements and risk reduction in products and systems.

Together, these standards ensure that colour coding and safety markings in electrical engineering are coherent, internationally accepted, and aligned with safety essential requirements.

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Keywords: EN IEC 60757:2021, colour designation, electrical engineering standards, letter codes for colours, electrical equipment marking, technical documentation, colour coding, safety publications, IEC colour codes, electrical safety standards, green-and-yellow colour, RGB colour codes, IEC 60445, electrical installations.

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
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