I'm not sure what you mean. Whether one is authentic in how they live their lives is not something others can always see.
As far as black/white, and shades of grey...for me, some things in life are black and white. There are things I simply don't do. There are things I always do.
These type of conversations always bring up outrageous hypotheticals. For instance, I say, "I do not steal. That is black and white. It's something I don't do." Then someone else says, "Well, if your children were starving to death, dying in your arms, you would steal food for them, wouldn't you?" To build this type of strawman to then jump to "So...see! Nothing in life is black and white!" is a weak argument.
When you say sobriety is shades of grey, I don't understand what you mean either. I suspect that might be because you and I have different definitions of sobriety though.
If I'm living my life in a way that coincides with my beliefs, then I'm living authentically. If my beliefs change and grow, and I abandon things that I did or adopt new ways of doing things, then I'm now also living authentically. It doesn't mean I wasn't living authentically before.