The 13th edition (1955) IEE standard specified white for the negative of a 3-wire D.C. circuit (i.e. what was at that time the second phase on A.C.). Positive was red and middle wire black, the same as the 14th edition standard.
It also specified that the outer -- of either polarity -- of a 2-wire circuit derived from a 3-wire system should be red. That was the situation which existed in houses fed from D.C. mains in the 1950s. Half the houses in the street would have a grounded black negative with red at +240V (ish) to ground; the other half would have grounded black positive with red at -240V to ground.
