The difference between blue ray and green ray.

[anagogy]

So if we see ourselves with brutal honesty, will even the smallest things seem very "evil"?

If you were seeing it without the cushion of self forgiveness that constitutes green ray, any of us might be completely shocked or crushed by seeming flaws in our character in either an STO or STS sense. In STO we might see that be faced with unpleasant realizations of how poorly we treated others, how lacking in love and self serving most of our behavior is for example.

In an STS case, they might be faced with realizations of not being as intelligent, powerful, beautiful, or skilled as they thought they were, or faced with the unpleasant realization of missed opportunities for evolution that were clumsily fumbled and lost due to their own incompetence and so on.

In either case, the gap between desire and reality would crush them psychologically with no compassion for self.