The diorama looks fantastic, its a great build and really well presented.
Mike, I think the green tint in uniforms comes from Gunthers box art. Gunther got that colour from a piece of original uniform. I've now managed to source a book that's new on the market which has a series of original images of uniform from the period and the colour is brown with a very light hint of green. When I get change I'll link to the book, but its by far the best reference to British uniform I've found, but the book will help clarify any issues. I've spoken to the publishers and they have allowed me to use some pages for my News from the Front newlsetter which will be out in April.
In terms of re-enactors uniform supply, I find them too brown for my liking (if that makes sense),
Just a minor note, in World War One Canadian uniform was the same supply as Britain, it was World War Two when the Canadian army used a greener version of battle dress.
But the diorama looks fantastic, I've seen 5 or 6 versions around and about, including this one:
I'm hoping to see more, I'm really pleased with the reaction to the set, there are a few things I'm working on now (improved instruction sheet, instructions for fitting bracing rods etc) but on the whole the reaction has been overwhelmingly positive.
I'll be at the British Model Soldier Society annual show in April, so my priority is to now get one built in time for that!