Different parchment color through Herbal section?

[Koen G]

Indeed. I guess you are looking at the Facsimile files, JPEGs from Voynich-Final-Sequential_ID-JPEGs 

Yup, those are exactly the ones I've been working with for a decade. I was unaware that part of them were reshoots - although that has never mattered much.

I've compared them to the 2014 jpgs from TIFFs you uploaded, it becomes clear that the 2015 ones stand out. Those should not be used for the current purpose.

I haven't quite figured out yet if these digital images can be used at all for this purpose. I suppose some matching properties between 2004 and 2014 would be relevant, but it's hard to see through the noise.