IEC 60757:2021规定了用于指定颜色的字母代码，并提供了用于指定颜色组合的字母代码的组合规则。字母代码旨在应用于电气装置、电气设备和产品的技术文件，以及电气设备和产品的标记。 本基本安全出版物侧重于安全基本要求，主要供技术委员会根据IEC指南104和ISO/IEC指南51中规定的原则编写安全出版物时使用。 它不适合制造商或认证机构使用。技术委员会的职责之一是在适用的情况下，在编制其出版物时利用基本安全出版物。除非相关出版物中特别提及或包含，否则本基本安全性出版物的要求将不适用。 本文件没有规定颜色属性编码的任何要求，也没有规定其视觉表示的任何要求。这些要求由不同的技术委员会负责。 IEC 60757:2021取消并取代了1983年发布的第一版。本版构成技术修订版。 与上一版相比，此版本包括以下重大技术变更: a)仅限于字母代码的代码； b)删除旧的不必要的票据； c)增加了关于同一项目交替颜色的新子条款； d)添加了附录A，其中包含颜色及其相应的RGB（红、绿、蓝）编码示例。

IEC 60757:2021 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.
IEC 60757:2021 cancels and replaces the first edition published in 1983. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) codes restricted to letter codes;
b) removed old unnecessary notes;
c) added a new subclause on alternating colours of the same item;
d) added Annex A with examples of colours and their corresponding RGB (red, green, blue) encoding.