BUR #20156 has been rejected.
create alias black_vs_white -> dark_vs_light
Making it a bit more inclusive for stuff like "black vs light pink", "dark purple vs white", or conceptually "dark vs light". Alternatively this can also be an implication to preserve strictly black and white posts.
Edit: This turns out to be more complicated than I thought. There's polar opposites which is like the umbrella tag, but there's currently no implication between any of the tags. There's also opposing sides which is just on its own. And that's where a lot of the posts I described end up.
Updated