Mark Zuckerberg is Colorblind:

Have you ever thought about why Facebook is Blue? You would find it shocking that it is blue because Zuckerberg the co-founder of Facebook is color blind. Technically, Zuckerberg is red-green colorblind, that means blue is the best color that he could see. Zuckerburg told that to a magazine site that, Blue is a rich color for me, I can see all of blue," he said in an interview.