You are that thick.
"Black Friday" is an age old reference to a "sale" around this time of the year, to move excess/old stock out, even at a discount, to move that cash to the ledger, thus keeping the books, and hopefully, the business, in the black. INK. Black ink, as apposed to red ink, a loss. No race element at all.
This language is new to some peoples. It is broad and inclusive. learn it.