Significat

1. A signalling device positioned at a road intersection or pedestrian crossing to indicate when it may be safe to drive, ride or walk, using a universal colour code.
2. A signalling device positioned at a road intersection or pedestrian crossing to indicate when it may be safe to drive, ride or walk, using a universal colour code.
3. A colour code using the three signals of a traffic light (green, yellow/amber, and red) as a metaphor.
4. The coloured dots on stamp sheet margins printed with offset litho or photogravure methods, used by the printers to check colour accuracy.