admin 
Update: The original post is below regarding the number one color that Bing a/b tested. After Bing, I also added an interesting finding from Google and what their preferred color may be.
The $80 million color is: #0044CC
That “code” is a precise shade of blue, and it works when a link is the call-to-action.
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.
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.
Source: CNET
Now, many times you’ll use a link as a call to action. This one shade of blue is the color for links. Keep it underlined. Don’t be fancy. Don’t mix it up with other colors either.
What has Google discovered?
Google doesn’t typically announce their split-test winners, but one site, GoodUI, closely monitors their changes. Based on a discovered change, this could be Google’s top pick.
Google has been using #1A0DAB for the SERP links for awhile and recently they were testing a blue close to #2358C2, but it seems to have been quickly removed. It stands to reason, that #1A0DAB is their champion (or control).
GoodUI theorized that it’s because this blue is darker than the other and provides a stronger contrast.
What’s the perfect color for buttons?
Orange, or a shade of it. Typically this color contrasts the best with websites. The color of your button is ‘set apart’ from your website. There are tests that have proven this countless times. Here’s a few posts:
- Split Testing with a Genetic Algorithm
- How to Call to Action (their explanation of why orange works best)
- The attack of red [actually, orange] buttons: how GSM.nl reduced bounce rate by doing a simple change
If you go to Bing’s homepage, you’ll notice they use an orange search button. It is likely that they also found that orange is best for buttons.
This is the power of testing. Use the above shade of blue for links. And, for buttons, it needs to contrast with the rest of the site — this color is typically orange.