Many thx for the pics {have added them to my 'personal' archives } especially the bottom one. Reason being is; that it supports the idea that any special painting of AFV's in the Great War was done on an individual basis, and not necessarily based on some formula....thx.
To attempt an answer to your query about colour....well, IMHO, I would think the lines of the 'net' camo paint would be either blaack, or a very dark reddish brown. I base this opinion on the fact that if you look closely at most of the 'net' lines that are over painted over the darker splotches of existing camo, you can see that the lines stand out against this colour....hence, it must be of a darker colour..........