So reading that link, there is no actual penalty. It is only a result of the average family income and size and the actual tax codes have no racial component. I would be curious if by the raw numbers of black/white families show more actual white families are affected, but as a percentage it skews toward black families.
It seems to me that the tax code could get really screwed up if they started chasing these statistics with the tax code. I guess that is probably the point.
The best solution is to just ban the income tax and eliminate the 16th amendment.