How many colors in high definition Television?

HD television is captured and stored as a component signal using 20 bits. The separate bits are used in such a way that the data can store what is effectively a 30 bit signal so there is a theoretical 1 billion colors available.

HD video in the studio requires a bandwidth of 1.5Gb (1500 megabits per second) and for transmission, this needs to be compressed to signals that are around 5 - 6 megabits. In doing this compression, much of the color information can be lost so 1 billion colors are never seen on a domestic television. That is rarely a problem as our color perception means we are quite happy watching programs with much less color information.