Yes Gilbert that was a tall tale. The PRR was very strict when it came to ailments relating to eyesight. You would not be hired with any color deficiency however if you developed it during your service years there were several options such a being restricted to the yard or put out of service on disability. NYPenn and the north and east river tunnels plus Wash terminal were color light territories on the Pennsy.
Regarding new signal practices. The new LED signals on my railroad are terrible in bright sunlight and way to dim. All complaints fall on deaf ears. In the old days they had night voltage and day voltage built into interlocking signals with day voltage amped up so you could read the aspect easier in direct morning sun light. When I mentioned that in a safety meeting everybody looked at me like I had two heads. Typical off the inexperienced non operating managers of today. Don't pester us with any old school operating regimens. We have a pathological aversion to that old stuff. We have college degrees, you unwashed union BLET bums. Am I too cynical? LOL