The patches of the darker colour look substantial, and the sponson looks pretty even in shade; I'd say it was painted one colour and has weathered. Doesn't look like camo.
Second photo - is that camouflage or just damage/weathering etc?
Like anything colour-related (it seems) there is no substantial evidence one way or the other. It looks like camouflage to me, but that's just my opinion. I can't see how that pattern of splotches could be made by a trick of the light, or the lens, or the photographic film. I am sure I have read (although I couldn't for the life of me say where, or in what book) that the tanks in Gaza were camouflaged by daubling patches with oil and then throwing sand on, so that it stuck in the sticky oil.
I think it was Swinton in "Eyewitness" who mentioned that the EEF tanks were camouflaged by throwing sand against wet paint.
The tank in the photo is HMLS War Baby, which was knocked out on the slopes of Outpost Hill, south of Gaza City on 19/4/17. The tank made two attacks on the hill, but Turkish fire was insufficiently suppressed to allow the British infantry to occupy the position. The uppermost photo gives a good impression of the terrific field of fire available to the Turkish defenders. The view encompasses much of the ground over which the British attacked during the 2nd Battle of Gaza, extending south towards the Tank Redoubt and Attawine Hills.
The Tanks site (what you are calling mailer.fsu.edu) has not been updated for years, since before this forum got started and probably even beyond that. But almost every photo and almost all the information comes from this book:
Tanks of the World 1915 to 1945, by Chamberlain and Ellis