It looks like Google is testing blue snippet headers in the mobile results. I believe this is an ongoing limited test but I figured I'd share it. Here are screen shots from Valentin Pletzer on Twitter of this in action.
He shared a couple of screen shots on Twitter:
Google testing blue headers for some results. Looks like the first results of each section (ads, organic) #google #mobile #serp cc @rustybrick pic.twitter.com/EFI2lOfEWU
— Valentin Pletzer (@VorticonCmdr) May 29, 2020
I am not sure I like it but for some reason it reminds me of the Google sidebar test.
Forum discussion at Twitter.