I've created a file in which I am using a master page with a graphic inside a frame; this appears on every page of my document. however, when I export it to pdf (interactive or print), the graphic changes color on two pages - it becomes lighter:
(correct color on the left)
there are no text boxes or other frames on top of this graphic, though there is text and other images placed on the page. As a test, I deleted an image (while leaving another image, as well as text) from one of the pages this is occuring on, and when I exported it, it went back to normal. So, I placed a new frame, re-inserted graphic, and I'm back to the same problem again.