Though I think it is easy to point out those who are definitely more of a black area inhabitants.
This phrasing made me laugh. :D
But yes, there is a spectrum of good to bad, at least based on social order and convention - and when people are intentionally harming others, well - it is pretty obvious.
For some reason it is harder to identify those who reside in the white spectrum. I guess those who work for charity or donate most of their money?
I wonder if it is harder because we become more blind to them, making assumptions about the kind of person they are, based on the position in society they hold. Look at the many "god-fearing" people who abuse children who trust them.