Mother Jones has the numbers, which apparently result from some lawsuits banning discrimination:

Turns out that there are some that, due to demographic changes over the century and a half since most were founded, are now white enough to bring their very designation into question: There are institutions that are classified as HBCUs with White enrollments above 80% of the student population (e.g., Bluefield State University, West Virginia 88.8% and West Virginia State University 83.2%)”. Ten percent of the HBCU population, over all, is now white.

The writer continues, “It’s all I can do not to wail, ‘Can’t we please have something that’s just ours? Please?’” Well, no, you can’t, unless we pass a law that it’s OK to completely ban whites from an institution. Presumably, the author would prefer such a law to not also make anti-black rules legal. We’re for the time being a majority-white country, so it’s not likely we’ll rubber-stamp that level of disadvantage for most of the population. Affirmative action is unpopular enough, and it barely affects a white person’s odds of getting into a given school.

I did find this amusing, though: At each school there’s a “minority affairs office which helps whites navigate their majority black college world.”