I reshot the images with a new color checker passport. Here are the imatest evaluations. Processing was grey balance, +0.25 exposure, black level -1 saturation -12, I believe, report exact values next year.
OK, here is the rest of the story:
I measured the actual orange using my Color Munki Spectrometer and found out the LAB coordinates. I took the corresponding part of the image and smeared it out using a large diamater Gaussian. Converted it to Lab and checked L. Created a selection and filled with "ab" values read by Color Munki but using L value from photograph and got a virtual match. End of story.
Erik. the fact that you have processed the images and I assume you have converted to sRGB sort of invalidates any comparison? Instead of using flash would daylight balanced lights for illumination and no processing be a valid way of making a comparison. I haven't used flash on oranges but I am thinking that the flash and the prominent orange colour would give you problems.