Trip information mpg consumption

Hey y’all I apologize if this is not in the proper place to ask this question I recently purchased a 2016 Toyota Corolla L with the six speed. It’s the wife’s car but I drove it home when we picked it up and I want to say that when I was looking at the trip information where it gives your mile per gallon consumption in real time it would turn green if you were getting good mile per gallon yellow if you were under medium throttle maybe red if you were Wot. maybe it only turned green and yellow. I can’t remember I’m in the car now on a road trip for about six hours and the bar is staying only yellow can someone confirm that this is Operating correctly because I swear it turned green because I was playing with it on the way home. maybe I’m mistaken or confused any help would be appreciative. I’ve searched Google and YouTube and the owners manual With no luck. thank you