Don't know if this helps at all Mikey, but on Railfan Europe there are some colour pics of the CFVE:
There's a decent pic of one van-type wagon that looks like terra cotta in colour, with black framing. Also, I am pretty sure I have seen a pic somewhere of a similar wagon but light grey in colour.
I guess the key to it is to vary the colour(s) slightly to give the impression of fading due to age and/or varying degrees of dirt and grime.
Having said that, bare wood and rust appear to be a very popular scheme on the CFTVD!
Edited to add:
http://www.railfaneurope.net/pix/fr/museum/CFTR/pix.html - some wagon pics towards the end of the page
Fat Controller of the S&CGR