You're reading the documentation for a version of ROS 2 that has reached its EOL (end-of-life), and is no longer officially supported. If you want up-to-date information, please have a look at Humble.
General Use ROS Artwork
The ROS 2 media kit, which includes branding language, high resolution ROS logo graphics, and release images, can be found in the ROS art repository. Please refer to this repository for ROS art work and our branding guidelines.