On aerodromes, which sign color is never used for mandatory instructions?

In the context of aerodrome signage, the color that is never used for mandatory instructions is green. Aerodrome signs are designed to convey important information to pilots, and the color coding plays a crucial role in ensuring that instructions are clearly understood.

Mandatory instruction signs are typically represented by a red background, which is universally recognized in aviation as indicating a stop or a prohibition. This makes it imperative for pilots to understand and comply with mandatory instructions to maintain safety on the aerodrome.

Other colors serve specific purposes as well. For instance, white is used for information signs, while blue is commonly associated with services available at the aerodrome, such as fuel or maintenance. Understanding the meaning of these colors helps pilots navigate and comply with aerodrome rules effectively.

In summary, green is not used for any mandatory instruction signage, reinforcing the importance of color coding in providing clear and immediate instructions to pilots in an aviation environment.