Thanks for the link to the article, I bought the digital download version of the mag. It's a good read, although the representation of the PC10E on Barker's Snipe doesn't look anything like the original in the Canadian War Museum IMO. This is allegedly original fabric and to my eyes it had a distinctly greenish cast to it. Definitely not the colour shown in the magazine. Mind you, the front part of the fuselage of Barker's Snipe has been overpainted with a PC10 ish colour, so I guess we can't say for sure that the remaining fabric on the fuselage hasn't been "restored" at some point. It doesn't look like it, although the museum did not respond to my email asking about the originality of the fuselage.
Personally, I prefer to reference original artefacts where possible. For example, the DH9 at Le Bourget, which is again allegedly largely original and distinctly khaki brown rather than greenish brown (see photos here:
http://www.wwi-models.org/Photos/Bri/DH9a/index.html). However, this is subject to around 100 years of deterioration since it was first in service.
Recently, I saw a very interesting original artefact at the RAF Museum, Hendon. It's a violin. Yes, a violin. Now why is that relevant? Because it's a violin built by an aircraft fitter working at the front using materials that were to hand. And on the reverse he has painted a pretty good representation of an AW FK8. He must have used the paints they had in store, and the colour of the plane is a brownish-khaki. Considering the violin will likely have been kept in a case and not exposed to sunlight, the colour is likely to be close to the original, and I can only assume that he used their PC10 paint to represent the aircraft on the violin.
There's also a lot of reference to chocolate brown with regard to PC10/PC12 and the assumption that would be a dark brown colour. Chocolate, like PC10, comes in a lot of colours. I've attached a copy of an ad for the original Fry's Five Boys chocolate, first released in 1902. You can see this is a light brown (milk chocolate) rather than a dark brown. This isn't far off the colour of the FK8 on the violin mentioned above. So any contemporary descriptions of "chocolate brown" do not to my mind necessarily mean a very dark colour. Alex Revell stated that WW1 pilots he met said the PC colour was brown rather than green. Also that Grinnell-Milne remembered that some of the last SE5as issued to 56 Sqdn were a very dark chocolate coloured brown. He remembered this as being different from the norm.
My own view is that the "accepted norm" of PC10 starting green and then going brown can't really be substantiated. As long as your PC10 is olive drab-ish, I would say that's fine by me.
The PC12 discussion is interesting. The article states a report which cites PC12 as "red brown". It's interesting that the Wingnut Wings kit instructions for the Camel and the Snipe state PC10 or 12 were used, and that "previous reports of it (PC12) being red brown are in error". They don't explain why though. I would not describe the fuselage of Barker's Snipe as dark chocolate brown. So still as clear as mud, or maybe dark chocolate......