I can answer that. This brake van is in its privatisation subsector colours which was generally seen (In these colours) in the 1990's. By then, the only brake vans seen on the network would be fitted ones so if the brake van was used with this train and used when the loco and its wagons were in the livery as seen, it would have been in the brown livery.
There were a few brake vans unfitted that were occasionally seen that were more likely to have previously been used by the old "Big Four" companies prior to British Railway being formed in 1948 (Later re-naimed "British Rail" by the time the 1970's to 1980's came along (Not sure exact date but think it was the latter half of the '60's that the name change took place, which was when the double arrow symbols took over as a livery and the B.R. blue came in on the locos and blue/greys came in (Or blue) on the coaches. Seem to remember all ovef blue meant something like the old coaches that had no vestible doors so one couldnot walk from one to the other? And if they had these corridor connecting vestible doors they would be blue and grey? Someone else who remembers more can say if I am right or wrong on this)).
