a substance occurring in plant or animal tissue and producing a characteristic colour, such as chlorophyll in green plants and haemoglobin in red blood. any substance used to impart colour.
4 bits are required. 4 bits can represent 16 different values (2*2*2*2 or ). 3 bits can only represent 8 different values. In the general case n bits can represent values, or correspondingly m values can be represented by bits.
