When I was a kid I often visited the family firm where a lot of users performed various functions on an S/38 mini-mainframe by means of dumb terminals connected

When I was a kid I often visited the family firm where a lot of users performed various functions on an S/38 mini-mainframe by means of dumb terminals connected with Twinax (I was seven or eight, I don’t remember the part number of the terminals). Anyway, long story short: everybody had the traditional green-phosphor-on-black displays, except one person, who had an orange-phosphor-on-black display. When I asked up-front about this (as seven/eight year olds are wont to do) it was explained to me by this person that they were colourblind and that an orange phosphor display had been procured for them to make the experience more pleasant.