Blue color is used in many product designs and logo designs such as Facebook, Microsoft, Twitter and our site. Why do companies choose blue color in their design? It's not a coincidence for them to choose blue. One saying is the color blue is associated with trust, efficiency, clarity and simplicity. Beside this reason, are there other reasons?
From an interface design standpoint, blue is an incredibly useful color. Among the dark colors designers have in their toolbox, red, orange and green already have strong built-in associations such as error, caution/safety, success. Brown is generally too close to black to functionally stand apart.
The other two dark colors blue and purple are left. Purple is a viable interface color, for example Apple uses it sparingly on the iPhone, but many people think it's girly and reject it outright.
From human vision point of view, the blue edge of the spectrum is useful because humans can see it but can't see it as well as other colors.
Specifically, we evolved to see reds and greens effectively. Reds and yellows can be signals of danger. We're especially good at distinguishing shades of green, possibly because it helps us move about jungle or grass, and can be a signal of food and water. We've evolved to see saturated blues and purples as something we notice out of the corner of our eyes
In practice, that makes blue very useful for UI: if you have a blue background, your eye tends notices the text, and not the blue. Try the same effect on a red background, and you may find it's harder to read the text.