I agree that the colors do seem weird for fear. It probably is the result of the weird mix of mechanics underlying the fear stat. I think it's worth noting that fear and obedience have similar usages and the dev has stated as much. Low fear could represent a problem if obedience was also low; however, fear slowly changes into obedience over time so it seems reasonable to expect it to be low for most slaves.
If stats are colored according to their usefulness to the player, then like obedience low fear would be red and high fear would be green. But problems are generally indicated by orange and red colored statuses, and it's not the case that low fear is a problem.
I would be in favor of either matching obedience's colors or using the higher value between obedience and fear to select the color for both lines.