How many colored drawings are required for utility patents?

Utility patents do not require colored drawings at a mandatory level. The United States Patent and Trademark Office (USPTO) typically requires that any drawings submitted as part of the application be in black and white, unless color is deemed necessary to understand the invention.

If color is essential for the understanding of the invention, the patent applicant may submit color drawings, which should be accompanied by a request for a filing date and payment of the appropriate fees. The USPTO allows up to one color drawing with the requirement that it provides clarity and is necessary to convey the information regarding the invention.

Thus, while an applicant might choose to submit multiple drawings in color, the question about the mandatory requirement should be seen in the context of necessity and clarity, rather than an arbitrary minimum set by the Office. In light of this, the answer provided does not align with the USPTO guidelines. The correct approach is to understand that while colors can be permitted, there is no specific quantity mandated for utility patents.