If you saw any blue badge employees with a yellow/red/purple border around their badge, then that signifies how long they've been at the company.
Saying someone is a yellow badge badge is saying that they are a full time employee with 5-9 years of tenure, most SDEs don't work with contractors so we don't talk about yellow badge contractors all that often.
If you're interested in this sort of thing, the color is actually supposed to be orange, but the color came out yellow.
Honestly, I never ran into many blue badges down in logistics. Mostly all white and yellow badges, with a few exceptions... and most of the time I was in and out so fast I wouldn't have noticed any colored border on their badge. The only time I would've interacted with a blue badge is if there was a problem on-route.
TL;DR DSP drivers don't encounter many blue badges.
The article you linked is from five years ago when the new badges were being initially tested. They have been rolled out for years with color photos. Both styles still work and if you don't go into one of a few big offices you might not have easy access to the newer style.
I've worked at two different facilities in CA and never once seen those. We still used the white/yellow/blue badge scheme.
Are there any ambassadors in this thread who know what those are?