Meaning of colour codes

Hi, I’ve been flying a DJI Spark for over a year. First time using this site so I have an embarrassingly basic question. In my flight log, some battery cell values are given in yellow. I don’t know what that means and can’t find a code that explains it. I’m trying to find out why the drone stopped suddenly with all kinds of warnings going off.

edit: The yellow values begin at around 8m50 secs.

edit2: I’m aware that yellow denotes the value is less than 3.5 V, but that didn’t trigger any warnings so is it just a caution?

It’s just to help you see where the battery was low when reviewing a flight log. You didn’t see any warnings in DJI GO since that color is being set by me in my flight log viewer.