A Short Statement
Balance of color is a technique utilizing color theory with the color wheel in order to adjust the intensities of the colors for photography, paintings, interior design, industrial design, etc.
Source: The Design of Everyday Things, by Don Norman
Source: Munsell Color Blog
http://munsell.com/color-blog/grammar-of-color-munsell-intro-balance-color/
Source: simplephotoshop.com
http://simplephotoshop.com/elementsplus/en_US/color-balance.htm
A Visual depiction from an original source
Source: simplephotoshop.com
http://simplephotoshop.com/elementsplus/en_US/color-balance.htm
A visual depiction from a non-original source
Real Life Example