If you go down to the Tate Modern today, this installation will greet you. All the pre-publicity described it as terrifying, but it is essentially a very large, unlit metal container into which you ascend. It's not very terrifying and it's not actually very dark. Your eyes soon adjust and easily discern the other people therein. A couple of years ago, I walked into Anthony Gormley's steam cloud cube at the Hayward Gallery and was completely disoriented. I couldn't see beyond a couple of inches in front of me and people were consistently bumping into each other. It was an eye-opening experience. Photograph taken by Stephen White It turns out that black isn't necessarily dark and that white can be. Marketers should be very pleased about that. Too often, they're not. Addendum: And sometimes, like art critics, they even get indignant if their users don't react as expected or, worse still, told.