Written by: Caleb Gilliam-Scott
Since October 1st 2025 the European Patent Office (EPO) has begun accepting patent application drawings in colour and greyscale.
Previously, coloured drawings were converted to black and white for publication, which could result in a loss of information if features relying on colour were not adequately identified in the description.
The new procedure applies only to drawings filed electronically; colour drawings submitted on paper by post will not be eligible. Additionally, colour drawings must be “sufficiently rich in contrast” and suitable for clear display at a resolution of 300 dpi.
Any colour or greyscale drawings filed electronically on or after October 1, 2025, will be available for public file inspection in that format. If a European patent is granted based on colour drawings, the so-called “B” publication of the patent will also include the drawings in colour.
These changes apply only to drawings; the use of colour in the description, claims, or abstract remains inadmissible. While not refused, such sections will continue to be published only in black and white.
The EPO will adopt different approaches depending on the origin of the patent application: whether filed directly with the EPO, as a PCT application filed with the EPO as receiving office, or as a PCT application entering the EPO regional phase. For subsequent processing of PCT applications in European proceedings, colour drawings must have been made available on PATENTSCOPE, and the international publication must include a statement that “the international application as filed contained colour or greyscale and is available for download from PATENTSCOPE.”
Care must also be taken not to introduce colour drawings when the priority application did not contain such colour. The EPO however will also begin to issue certified priority documents with colour drawings (both electronically and on paper), where used.
Whilst many may focus on colour as the headline win bringing new visual possibilities, it is arguably the accompanying acceptance of greyscale that offers the greatest practical benefit to applicants. For computer-implemented inventions in particular, screenshots have become common features of patent figures. Yet under the previous binary constraints of black-and-white, such figures often attracted formal drawing objections, forcing applicants to convert screenshots into line drawings, a compromise that could strip away valuable detail and context.
With greyscale now expressly permitted, applicants – especially those pursuing global filing strategies – gain welcome flexibility. And fittingly, even before the new rules, the status of greyscale drawings was something of a grey area (pun intended).
The acceptance of colour and greyscale drawings continues the trend of increasing digitalization at the EPO and reflects a modern approach aligned with real-life practicalities.
