SAN FRANCISCO — Google users have noticed something different about the search results being returned at the moment: They are not the iconic Google blue, but black instead.

The Silicon Valley giant appears to be A/B testing black links for its search results, much to the disappointment of many users.

The test replaces traditionally blue link titles with black ones. The body text and link addresses remain unchanged, being black and green respectively.

Google puts a lot of thought into the exact colours it uses in its services — and for good reason. A few years ago, its A/B test of different shades of blue — nicknamed “50 shades of blue” — earned the company an extra US$200 million (S$274 million).

Designers at Google could not decide between two different blues, so they decided to test 41 shades between each blue to see which users preferred. In the test, Google showed each shade to 1 per cent of its users, and found that users were more likely to click on a slightly more purple shade.

In a more recent test, the company last year spent months trialling blue navigation links before it finally replaced the red ones for all users.

A spokesman for Google said the company is “always” testing small changes to its results page. On this occasion, admits Google, “We’re not quite sure that black is the new blue.”

Google is not the only major technology company to carry out A/B tests on its users. Netflix recently admitted that it tests six different images for many television and movie titles, and rolls out the one that most viewers click on.

Facebook has also conducted tests designed to emotionally manipulate users by highlighting positive and negative emotions, while OK Cupid has deliberately matched incompatible people to see the outcomes.

There is not a blanket way to turn off Google’s A/B testing, but users on a Google search help forum have reported that logging out of their Google account and back in again reverts the links back to blue.

A Reddit user also reported that disabling “Your searches and browsing activity” in Chrome’s settings turns the links back to blue. THE TELEGRAPH