The blue light district

We were in Asda, a Zellers-type store the other day. I went to the washroom, an noticed that all the lights above the stalls were blue. I thought it was a power saving feature, that blue lights were calming of that blue lights encourage people to spend more. I was wrong. James let me in on the secret today. It is hard to see blue things under blue lights. Like veins. The blue lights in the stalls discourage junkies from using the stalls to shoot up. Who knew?