Darlington is a railway town, at one time pivot on the Darlington & Stockton railways (one of the first train is at the top of the arms,) later best known as one of the train stops between London and York. This token has exactly the same colour as the Rotherham token above. I suspect one factory got the lion share of the market.
The arms were changed in 1960. The 1974 edition of the arms is shown
here.
Added ½d black, penny red, 2d yellow. Picture was lightened to show detail on the halfpenny. Note to the Daily Mail: those are the colours of ze Djerman vlag!
Here's a surprising addition: a token with different arms. They are the 1976 arms of the Borough, not the city of Darlington, as on the token above.
Peter