The European Patent Office (EPO) will accept color drawings

The European Patent Office (EPO) announced that it will accept color and grayscale drawings in patent applications filed electronically from October 1, 2025. “Drawings submitted electronically may also be processed in color or grayscale, provided that their lines, strokes or areas are durable, uniform in thickness and clearly defined. In addition, the drawings must have sufficient contrast and be legible at a resolution of 300 dpi.”

The permission to use color drawings in European Patent Applications (EP) has long been a highly anticipated development, marking a relaxation of the previous requirement that only "colorless drawings" could be used in European applications. Although color drawings are already permitted in practice, under the current examination guidelines, the EPO only allows drawings published in black and white for examination, which means that any information relying on color is at risk of being lost.

Starting October 1, 2025, color drawings will be explicitly permitted and treated as such, which will be particularly beneficial for applications that rely on the presentation of scientific data, as color will help present the information more clearly.

It is worth noting that different IP offices have different levels of acceptance of color photos and drawings. For example:

• The Korean KIPO is the only intellectual property office that generally accepts color drawings in specifications.
• The USPTO and CNIPA accept color drawings only when color is essential to explain the technical content of the application.
• The Japanese JPO does not accept color drawings and requires black and white line drawings or grayscale images.
• The UKIPO currently does not allow color drawings.

PCT international applications have clear requirements for black and white line drawings. While color drawings may be accepted under special circumstances, the drawings will still be converted to black and white line drawings during the international publication process, and must meet the requirements of the relevant patent offices when entering the national phase. It is understood that technical preparations to allow the submission of color drawings in PCT international applications are currently underway.

Therefore, while the EPO's move to allow colour drawings in European patent applications is a significant and welcome change, applicants wishing to file in multiple jurisdictions will be better off continuing to adhere to the stricter black-and-white requirements until other patent offices adopt the same practice.