COLOURLovers has conducted a fascinating study of the dominant colors on the Internet by analyzing the palettes used by the top 100 brands on the web as determined using Alexa, Compete, and Nielson ratings. Their findings, as you can see in the graphic above: Blue and red dominate, while other colors like green and purple are relatively rare.
Why? There may be no shortage of pop-psych explanations for this color distribution -- say, that red symbolizes power and authority, or that blue stands for safety and modernity. But the author of the post points out that many of the companies in question have stuck with the same basic color scheme since they were scrappy startups, unaided by branding research: Mark Zuckerberg, COLOURLover notes, claims to have made Facebook's color scheme blue because he himself is red-green colorblind, a fact corroborated in his recent New Yorker profile. Then again, when Wired analyzed the colors of corporate America in 2003, they also found that red and blue prevailed.