Yeah, it's totally 100% without a doubt black. I don't feel great about being mislead, but it's in great condition and less than $100 after the discount. See how easily I can justify unscrupulous behavior? Bags are not a thinkin' (wo)man's game!
It is hard with color.
On my computer the bag look black, but on my iPad look very dark brown. Your seller was probably did not have the intention to mislead you, but again, is hard with color.
One time I sold an Louis Vuitton Epi that Louis Vuitton called the color as Vanilla, and to me the color is also Vanilla, but the buyer said "item not as described", she said the color is yellow and not Vanilla. I have no idea what this person think the color of Vanilla. I took the bag back and issued full refund.