Color in reality is about the way that we humans perceive various frequencies of light and how we perceive combinations of frequencies. Color in art is about how we use those perceived frequencies and combine them to define shapes, create spaces, and – a fundamental aspect of art – to communicate emotions and create atmosphere. When using a computer to create art, an artist uses color in much the same manner as does an artist using paint, at least in terms of design. The differences lie in how each artist manages colors. When thinking in terms of computer vision and analysis, where we want a computer to do some interpretation of an image or scene, color is a feature of each region and pixel that might be related to other pixels.