James, do you have a source for the colour information? The L&Y wagon books describes as "hearsay evidence" that the first 50 may have been painted a "very light pastel green." There is no reference to the roof and that seems somewhat unlikely. I obviously have an interest having the 7mm version.
John
The reference to the roof comes from the history/livery information provided in the kit instructions by David Geen: "The green even extended to the roof". It surprised me too!
The photo on page 386 of the wagon book, showing a rake of fish vans, references two of the rake as being "probably green". That same photo shows a freshly painted white example, whereby the roof matches the body and I guess the implication there could be that the white livery followed the pattern set by the green examples.
Page 375 references the colour coding of perishable vans, although does not mention roof colour.
Nigel Digby references the various van colours in his third "Liveries of the Pre-Grouping Railways" book, but again, this does not specify roof colour.
Additionally, I have seen someone else model a red gunpowder van with a red roof to match (whilst I know you should never model a model, it has to have been based on something) and so, between that and the David Geen comment, I've deduced that the special liveried wagons had their roofs painted to match - Or at the very least, that's how I'm planning to model them currently.
I hope that helps?
- James