[agemame]

Originally, blue screens were blue because it was something that could be chemically dissolved from film negative stock without doing much damage elsewhere (Superman when he flew was slightly teal at one stage to account for it).

Certainly when Midway Games were building a digital rig for CPU digitisation of footage for their arcade games, they started with grey and a lumakey, then experimented with blue, but found floor reflections were an issue. I think eventually they settled on a matt floor like the ITV News table, but eventually moved to green for the same reason as here i.e. comping out blue lost too much data.