A example of color banding, visible in the sky in this photograph
Color banding is a problem of inaccurate color presentation in computer graphics. In 24 bit color modes, 8 bits per channel is usually considered sufficient to render images in Rec. 709 or sRGB. However, in some cases there is a risk of producing abrupt changes between shades of the same color. For instance, displaying natural gradients (like sunsets, dawns or clear blue skies) can show minor banding.
Color banding is more noticeable with fewer bits per pixel (BPP) at 16–256 colors (4–8 BPP), where not every shade can be shown because there are insufficient bits to represent them.
Possible solutions include the introduction of dithering and increasing the number of bits per color channel.