Colour association forms an important: part of colour language in all areas of graphic design. This can be seen in the way that greens are used for freshness, blues and whites for hygiene, red for danger, and purple for richness. There are many examples of colour combinations that are associated with politics, nationality, sport, religion, or cultural and social conventions. The designer has to be aware of all of them, in order to avoid creating confused messages. For example, red and green are recognized across the world as symbolizing 'stop' and 'go'.