It's easy for people to say accept being called Black when they aren't Black, meanwhile they hate being called something they're actually part of.
It's easy for you to say Black isn't a negative when you're not the one who's constantly reading or hearing people use the word Black as part of a negative thing in everyday conversations:
*Black sheep of the family
- Blackmail
- Black cloud
- Black Sunday
- Black mood
- Black heart
- Black market
- The black cat/dog curse
- Blackening someone's
name...
*Blacklist
*Black soul
*Blackballed
*Black death
*Pot calling the kettle Black
*Black as sin, etc.
Even 'dark' is still used in a similar way but don't have as many words.
(Acknowledging @Blackisblackisblack because I stole part of this from you. Thanks for it.)
As a non-Black person, you don't know how it feels to see these things and be reminded that you're a Black person. No, to you, it's fine, it's all innocent, it's just a coincidence, doesn't mean anything. Actually, you don't even think about this because you rarely notice it. Why would you?
As a non-Black person, you give the platitude Black is beautiful, be proud of being Black (whatever the hell that means), yet on the other hand, you'll use Black as the opposite of beauty and white in the opposite way: white lie, white feather, white Knight, etc. Yes, it's so great. Why don't we switch colours?
I don't think a non-Black person should be telling a Black person the label they should or shouldn't accept. It's not up to you because you're not the one sharing the label with most things considered bad or evil. Even angels are all dressed in white. White is used as the symbol of purity, innocence, etc. Black is used as the symbol of doom, hell, Satan, demons, horror, etc.
I love the colour Black as a colour, it's one of my favourite colours to wear (I also have black hair) but please don't come into this conversation as a non-Black person essentially telling the people labelled "Black people" to suck it up and like it. If a Black person wants to be called Black, that's great. Nothing wrong with it.