I have to say I'm glad Gaugemaster are changing the roof colour on 73101 to white but it would be nice to keep the fibreglass panels that grey colour!
With regards to the livery on 73101 when it was originally painted into the Pullman colours in 1991 (at Selhurst I believe) it had a white roof and yellow lining/numbers. The second time it was painted in 1997 (at Stewarts Lane) it featured a silver roof and gold lining/numbers and to be looked far more authentic!
So the model itself with what looks to be yellow lining/numbers and a white roof will be accurate for 1991-1996.
Darren