LAS VEGAS--Microsoft often talks about the importance of search being more than just 10 blue links. However, it turns out that at least the "blue" part of that is very important.

When Microsoft was designing what would eventually become Bing, it tested a vast number of colors and it turned out that the one that users engaged with the most was indeed blue. More specifically, it was a shade of blue quite similar to the one used by Google.

Screenshot by Ina Fried/CNET

Paul Ray, a user experience manager for Bing said on Tuesday that choosing that specific blue (#0044CC for you color enthusiasts) over some other hues amounted to an additional $80 million in annual revenue, when one factors in the additional clicks on advertisements and increased user engagement.

"That blue was worth at least $80 million," Ray said, during a presentation at the Mix10 trade show here.

The previous version of Microsoft's search engine--Live Search--had used a lighter shade of blue.

"It lacked a bit of confidence," Ray said.

In testing, it turned out that color and contrast were more important even than the typeface used for search results. Microsoft experimented there too, toying with Verdana before ultimately returning to the standard Arial.