Post a series that u find has no black and white areas but has gray areas instead, is shown through shades of gray

If u mean morals wise, I've always thought Black Butler was a series that pulled this off well. Everyone is extremely flawed with their own motives, there's no "bad guys" vs "good guys" since everyone is horrible of flawed in a sense.
Like the reapers are only hunting down Sebastian because they're doing their job, Sebastian is a loyal butler and helps Ciel with his goal but is only in it for his soul, Ciel is a wretched child but is a victim who went through many traumatic experiences, etcetera, etcetera...
There are very little characters who are evil just to be evil.