EDIT 2: See updated topic here
I saved out two versions of the same 3D render. One JPG and one PNG. The scene shows 2 wine bottles on a gray surface.
I create a new document in AP, in CMYK color space.
When I place the files into AP, the JPG looks correct but the PNG looks wildly off. Very low contrast and some odd color shifts. If I switch the document to RGB color space, both the JPG and the PNG look the same.
Linked PNGs seem to be rendering incorrectly in CMYK space, unle