Simply put, If one thing is adjacent to something else, then the something else is also adjacent to the one thing.
Thus ground is adjacent to sky is adjacent to ground. West is adjacent to north, east and south and the other way around three more times. And on and on it goes. Everything is adjacent in umpteen ways to numerous things.
So anything white folks use to describe other color groups as being white adjacent to them, then simultaneously white folks are describing themselves as black adjacent or brown adjacent or yellow adjacent or red adjacent or people of color adjacent or minority adjacent or.... You are connected and reflective from a different perspective.
Thankfully, white folks don't own the word white and did not create the word white and did not create the color white and are the least of the white gods.
Briefly speaking, the Milky Way is an ever-present White Way along with the Kau Moon of our Earthstar planet. Two of the incoming Lords of the White are Kepheus and Sekhet as part of the White Khuti. All of us are thus white adjacent to the above, middle and below; however, most of us are askewed up, down and crossways in our white adjacentness.