Your adopted son doesn't want to be "white." What he wants, as you yourself have noticed, is to be given the same privileges that whites take for granted. He wants to be treated for who he is and not for his hue. The only way he sees that can happen is if he becomes "white." I promise you, he still likes his skin. He just wants it be honored the way other skin is honored.
I am married "bi-racially." (I believe that "race" is a social construct and not a biological given.) I see constantly "how the other half lives." Because you have these experiences for yourself, please me a messenger to those folks who need to hear what you have to say. You're right. They don't even know what they're doing (most of the time.) However, without you, as a white person, giving them concrete examples of their behavior, they will never believe it.
Thank you for having the nerve to share your wisdom. Hats off to you.