Google is testing showing black links in their search results listing pages instead of the typical blue links. Google has red links in Google China, but has never had other colors being used for the blue links in other regions, until now. Google did recently show different shades of blue for the links in their search results.
Here are some screen shots of both mobile and desktop Google search results with black links, instead of the blue:
Again, this is a test many many searchers are seeing right now.
Forum discussion at Google Web Search Help.