[drewzero1]

Ultimately, wouldn't that just see which is the most popular background color? Pixel-for-pixel the background takes up the largest percentage of screen space on most websites.

Though I would also be interested to see what the most popular background colors are. My money's on white and off-white.

[kadoban]

You could, instead of counting pixel-by-pixel, count once per specified color. Eg count #000000 once per css rule it's specified in, once per image it's used in, etc.