Lots of cool pictures (many in colour!) and original WWI press articles here:
I especially like Artillery ones (Austrian Skoda 30,5 in Belgium in 1914!!!)
As my Varsovian friend said, this is a really cool site; good for hours and hours of browsing.
http://www.greatwardifferent.com/Great_ ... lor_06.htm
for a color photo of French anti-aircraft gun truck.