Yep, the thing is black and there is nothing more to say about it. You can take nice pictures because of the contrast with the blue sky and the colored mountains around.
Just an area of black rock in otherwise red stone. No real reason to seek it out. I guess it may be worth a drive by if you are already here. Definitely not a destination unto itself.
We enjoyed the drive there - on non-tarmac roads - and back from Twyfelfontein lodge but there is really not much to see. When we went there was a “parking attendant” who said it cost 150 Namibian dol...
Waste of time and money (100NAD) for 2 persons for a small black rock mountain and some interesting stone formation ( pipes)
The only good thing that may be said for this “attraction” is that it is included in the extortionate entrance fee charged to see the Organ Pipes (q.v.). Avoid.