East Japan Railway Co. has spent £100,000 fitting out all 29 stations on Tokyo’s central train loop, the Yamanote Line, with the strong bulbs.
The operators believe they will emit a soothing glow, despite the absence of any scientific proof that the method reduces suicides.
Mizuki Takahashi, a therapist involved with the project, said: “We associate the colour with the sky and the sea.
“It has a calming effect on agitated people, or people obsessed with one particular thing, which in this case is committing suicide.”
A total of 68 people threw themselves in front of trains in the 12 months until March, up from 42 in the same period the year before. The lights will be hung at the end of each platform, a spot where people are most likely to jump to their deaths.