Joost de Valk the founder of Yoast, spotted Google testing using blue navigation links in the main search results. Normally Google uses red, in fact, they always use red.
Here is a picture from Yoast:
You can click on it to expand.
While this has no real impact on rankings, this is actually a pretty serious visual change to the Google search results. I am sure Google will test this for some time and then decide to either go with it or not based on some usability metric.
Forum discussion at Twitter.