Colour drawings to be allowed at the EPO

The European Patent Office (EPO) has announced that, as of 1 October 2025, it will be accepting colour and greyscale drawings in applications filed by means of electronic communication.

The Decision of the President of the EPO dated 7 July 2025 on the presentation of application and other documents supersedes the previous decision setting out such requirements and introduces the condition that:

“When filed by means of electronic communication, drawings may also be executed in colour or in greyscale, in durable, uniformly thick and well-defined lines, strokes or areas. They must also be sufficiently rich in contrast and suitable to be clearly displayed at a resolution of 300 dpi.” [1]

Permitting colour drawings in EP applications is a long-awaited development, and it represents a relaxation of the previous requirement that European applications could only include drawings “without colourings”. While, practically speaking, colour drawings can already be filed, under current practice, the EPO makes them publicly available via file inspection in black and white only [2], meaning any information relying on the colour risks being lost.

As of 1 October 2025, colour drawings will be specifically allowed and processed as such, which is potentially of particular benefit to applications relying on the presentation of scientific data, for which the use of colour may assist in presenting information clearly.

It is worth noting, however, that rules regarding acceptance of colour photographs and drawings continue to vary across different Intellectual Property Offices.

For example, within the IP5, the KIPO in Korea is the only other office to accept colour drawings in general cases. The USPTO in the US, and CNIPA in China, will only accept colour drawings if colour is necessary for explaining the technical content of an application and the JPO in Japan does not accept colour drawings, requiring black and white lines or greyscale images [3].

Additionally, colour drawings are not currently allowed by the UKIPO [4].

Black and white line drawings are also an explicit requirement in international applications under the PCT [5]. Though colour drawings may be accepted in exceptional cases, they are nonetheless converted into black-and-white line images for international publication, and the requirements of the relevant national offices must still be fulfilled upon entry into the national phase [6]. Technical preparations for allowing drawings to be filed in colour in PCT applications in the future are underway [7].

In summary, while the decision of the EPO to allow colour drawings in European patent applications is a notable and welcome change, for applicants looking to file applications in multiple jurisdictions, it is still best practice to continue to adhere to the stricter black-and-white requirement where possible, unless and until other patent offices adopt the same approach.