It all has to do with what kind, and how much, lighting Factcheck used for each photo. I had the same problem with my photos.
Factcheck used a 5300K floodlight to illuminate photos #2 through #6, natural sunlight for #1, #7, & #8. Photo #9, the one you mentioned, however, was shot in low light, or ambient room light. The 5300K floodlight and indirect sunlight will give you more accurate colors than shooting them with incandescent light (reddish tinge) or ambient room light (which washes out the color).
One last note about the floodlight: as I mentioned in a previous post, there are a couple of shots that were imported into a graphics editor to create different lighting effects (in particular photo #1, $5, and #6).
The top part of the Seal (above the fold) in photo #5 shows all of the ridges and letters of the Seal to illuminated. Yet, in photo #6, only the oter ring appears to be illuminated.
There's no way to do that naturally. I tried every possible positioning and attenuating of a light source, and could not duplicate it.
The photographer did not use flash in any photos, and kept the camera set on macro mode the entire time -- which explains why photo #3 is out of focus. Using macro mode, they had photos as close as 10mm out to 3m.
However, where are the photographers out there? Why has no one raised the issue of how many photographs were taken ( test photos )that we did not see? discarded. We're talking about a digital camera that can rattle off about four times as many, if the allotted time in the Exif info is correct.
Was the cameraman so stupid as to NOT take another photo to replace #3?
Hardly, as they had every intention of shooting it out-of-focus.
This book is addressing what you described:
The Manual of Photography
http://books.google.com/books?id=HHX4xB94vcMC&pg=PA247&lpg=PA247&dq=photography+light+makes+green+look+yellow&source=web&ots=7Hk3txU-vo&sig=4jxSFdL9DeMMMSiTaYPZt-AcZXs&hl=en&sa=X&oi=book_result&resnum=8&ct=result#PPA257,M1
Messing with the light exposure and blocking blue and red would make the document look yellow. Which is probably why the pictures of the yellow COLBs have darkened backgrounds instead of the arms and tables you see with the green COLBs.
That link only shows excerpts of the book. I will go to the library now and see if I can find more.
The paper is at a different angle to the light. I'm still waiting for my answer on #5: was the embossing photoshopped or was the paper embossed and then photographed? The latter is the only plausible answer.
A forgery including an embossing tool is entirely possible but you would need to update your analysis to include that fact.