Traffic-light signalling and operation to a double red light. Tianjin in the People's Republic of China has two very special systems of traffic lights, in use since : One system is where there is a horizontal bar in a specific colour, with the colour changing and the bar shrinking. The shrinking bar indicates the time remaining in that colour. The colour itself is either red (stop), yellow or green (go). A blinking green one-third-full bar means "reduce speed now", and a blinking yellow full-bar indicates "proceed with caution". When lights of this system turn from green to red, the diminishing green bar will flash
Colour cast Colour cast A colour cast is a tint of a particular colour, usually unwanted, which affects the whole, or portion, of a photographic image evenly. Certain types of light can cause film and digital cameras to have a colour cast. Illuminating a subject with light sources of different colour temperatures will usually cause colour cast problems in the shadows. In general, the human eye does not notice the unnatural colour, because our eyes and brains adjust and compensate for different types of light in ways that cameras cannot. In film, colour casts can also be caused by problems in development.