A few things. You can count everyone's skin colour AFTER they have arrived at college. That is not about admission and it solves the problem you've made seem insurmountable. Sociologists would still be able to make the same cases. After admission they could also ask students where they applied and whether they got in. What is being argued here is that the application process must be race blind, not that race isn't a thing.

And it's precisely because the law is colourblind that this challenge can arise. You cannot under US law discriminate, where discriminatory practice is found it can be challenged using the 14th. That's what's happened. The skin colours of the various people involved doesn't matte to the law itself. You cannot use racial discrimination to solve racism - that's been my position for as long as I've written on here and it puts me out of line with the fundamental identity narrative of race writers.

Affirmative Action was always going to be time limited because it flies in the face of the 14th, but the subsequent wooly social engineering that has emerged as a result of identity politics sealed its fate. My contrarian thoughts are here if you fancy discussing it further. https://medium.com/lucid-nightmare/is-the-end-of-affirmative-action-really-a-terrible-thing-7d9595fe36e