It's Black. It's White.
Here’s some insight into how my brain works...
When I read the word “black” – this is what comes to mind:
Where are my black shoes? I'll wear my black gloves. I need a new black belt.
When I read the word “white” – this is what comes to mind:
I have a white envelope for you. Have you seen my white shirt? Put it in my white mug.
Now when I read the word “Black” – this is what comes to mind:
I am Black.
I work with a lot of Black boys.
Race may be socially constructed, but it matters and it's someone's identity .
So now let's talk about White people. You see I capitalized it. This is because white is a piece of paper, but White, is a person.
Some of my best friends are White. [see what I did there;)]
No matter how many differences between us or issues we may not agree on, I don't have to agree with someone to recognize their human experience.
When I am talking about someone’s racial identity, it matters to capitalize the race to provide a sense of humanity and cultural identity. To capitalize one racial identity over another, even in this day and age, just seems, well, wrong.
For more information on this topic and a deeper discussion, see this article by Ann Thúy Nguyễn and Maya Pendleton on the Center for the Study of Social Policy's decision to capitalize White and this article regarding Associated Press' decision not to capitalize White.