It develops an outraged tone.
Explanation:
The statement is clearly outraged at the racial injustice it is coming from and states that the education and college degree of a white man seems useless in declaring his ability to read and write because being able to pass these barriers relies more on his skin color than his own merits.
According to the passage, having a white skin pretty much guarantees one a degree.
So, it is not entirely by one's own merit that they get through to college but through the inherent privilege they have.