Thanks for your message. The fabric I have is most definitely not
from an aircraft with lozenge fabric. The colors quoted are paint
applied to doped natural colored linen and are most likely from Albatros
wings. I agree that the greenish shift in the blue color may be the
result of yellowing of the varnish that covers the paint. Unfortunately
after nearly 80 years the two are inseprable and seeing any "true" color
beneath the varnish is impossible.
Unfortunately as well, Methuen is all I have for a nearly standard
reference to colors, it is used widely in various publications. I was
fortunate enough to get a copy of the Methuen book when it was reprinted
in 1989. It may come back into print once again, who knows?
Charles Hart
hartc@spot.colorado.edu