Oryk,
I have 3 jepegs with colorclass red. Two of them are captioned with PM 4.5. I open them in Adobe lightroom. The two captioned jepegs kept colorclass red. The non-captioned jepeg lost its colorclass. Is it a PM or a Adobe abnormality ?
Did you set the color class on the one that lost its color class with version 4.5 or did you do it earlier with a different version?
Basically unless the image has our color class information tucked away inside the IPTC or XMP data, no program (LR or otherwise) is going to preserve the color class, tag, or rating if they update the file.
There is a preference in the Files tab of the Preferences dialog that you can set to make sure that when you change color class, tag, or rating that it will be preserved in IPTC/XMP data. It is near the bottom and is titled "Add tag, color class, and rating to IPTC/XMP:" followed by a popup menu. If you want this to work all of the time, then set the popup menu to "For all photos" and that should solve the problem.
HTH,
-Kirk
