I've seen this issue mentioned before:

Taken from this thread/blog post in comments from 2014:
HIDDEN GEMS IN ORION NETWORK ATLAS
New to Orion and I've been tasked with setting up some overhead/NOC displays. I'm experiencing the same exact issue on Orion NPM 10.7. When a metric exceeds a threshold, it shows the HTML tags for coloring it instead of actually doing anything. Changing the thresholds does not even affect this, I tried setting both thresholds to 100% and it still displayed this way. In my limited use I've only seen it for 'volumes' I.E. disk utilization and memory utilization. Unknown if it affects CPU or other metrics. It's been around for a while, is there any chance this is fixed on another version?
Thanks!