Red velvet cake is essentially a light chocolate cake. There are always a few tablespoons of cocoa powder involved to give it a subtle chocolate flavor, but not enough for it to taste like a proper chocolate cake. It also has a lot of acidic ingredients that can give it a bit more of a tang than a traditional chocolate cake (especially when it's classically paired with cream cheese frosting). The high level of acidity in the batter also means it tends to be very tender, rich, and moist. And then, of course, it's loaded with red food coloring, as our modern cocoas don't naturally make it quite red enough as some cocoas did in the old days (and modern expectations for this cake definitely tend toward more unnaturally red tones).