Color depth is one of the important aspects in computer graphics and digital photography. It is also called bit depth. Color depth can be termed as the number of bits in a pixel. Higher bit rate leads to high quality of image and high image size. Before going deep into colors I like to stress upon index colors. Index colors offers only black and white mode, In VGA system gray scale is possible.
The concept behind basic colors (RGB) is each color consists of 256 shades. There are 256 shades of blue, 256 shades of red etc. But human eye can detect only 100 to 150 shades approximately. To represent all the shades the minimum bit required is 8-bit (28 = 256). This 8-bit considered as low resolution now. As the bit rate goes on increasing the number of colors also increases which results in a better quality of image. 16- bit is called as HIGH Color. 16-bit color scheme uses 5 bits to represent blue and red. 6 bits for green since human eye is sensitive to green. So 16-bit color format represent 64 levels or shades of green. Primitive LCD display uses 18-bit color format. True color is an advanced format which uses around 16.7 million colors. True color is more than reality. They are used in mega pixel monitors and high resolution cameras.
