The World Diabetes Day logo is the blue circle - the global symbol for diabetes which was developed as part of the Unite for Diabetes
awareness campaign. The logo was adopted in 2007 to mark the passage of
the United Nations World Diabetes Day Resolution. The significance of
the blue circle symbol is overwhelmingly positive. Across cultures, the
circle symbolizes life and health. The colour blue reflects the sky
that unites all nations and is the colour of the United Nations flag.
The blue circle signifies the unity of the global diabetes community in
response to the diabetes pandemic.

The official logo is available for download in the materials section.