On a London Underground map, what colour is the Circle Line?

The Circle Line on the London Underground map is represented by the color yellow. This line, as the name suggests, forms a complete loop and connects various important locations in central London. The decision to use the color yellow could be due to several reasons. One possibility is that yellow is easily distinguishable from other colors on the map, ensuring clarity for passengers. Another reason could be that yellow is commonly associated with positivity and energy, reflecting the vibrant and dynamic nature of the bustling city of London.