Google is now testing highlighting portions of the featured snippets they show in the Google search results page. I am seeing the highlights both in yellow and blue format, as well as no highlights at all.

The first person I noticed who spotted this was Lily Ray who posted this screenshot on Twitter on Friday morning. Here are the screenshots, click on them to enlarge:

I was able to replicate this with a blue highlight format:

And of course, with no highlight at all:

Others also noticed this afterward, like:

I wonder if this is another form of featured snippet call outs.

Forum discussion at Twitter.