Which is odd, because X11 has all this visual and depth stuff leftover from the days of 1/4/8/16-bit displays, and mixing windows of each type on the same scree

Which is odd, because X11 has all this visual and depth stuff leftover from the days of 1/4/8/16-bit displays, and mixing windows of each type on the same screen. You would expect it to be capable of representing 48 bits just as well.