1. A method of determining a correction for a spectra of scene illumination based on analysis of color content of a video image, the method comprising: electronically considering two pixels at a time to determine pairs of neighboring image pixels that substantially differ in color from each other; electronically evaluating overall sums of color components of the image by adding values of each color component of the pixels of said pixel pairs; electronically determining an average image luminance by adding together luminance values of the pixels of said pixel pairs; electronically computing gain adjustments for said color components of the image in a manner that said sums of color components of the image are equalized and said average image luminance does not change; and electronically applying said computed gain adjustments to said color components of all image pixels, wherein said electronically determining is performed by sequentially inspecting pixel pairs along a scan direction of the image, wherein only pixel pairs comprising pixels of the same image line and having N pixels between them are considered for determining pairs of neighboring image pixels, and wherein N is an integer value from 0 to a length of an image line minus two.