I am composing a large number of pdf figures with
includegraphics that contain pixel graphics with xelatex. The individual figures are themselves compiled with xelatex using
includegraphics. As the original pixel graphics, the pdf figures have a colored a (light yellow) background.
In the composed document in some (but not all) of the figures the background appears in greenish color that I do not use anywhere else in the document.
How come that xelatex (pdflatex seems to do the same) replaces the background color of these figures and how can I fix or even debug that?
The document is big and I did not manage to reproduce the effect in a smaller file so far. I am using texlive on ubuntu. and experience this problem in with different pdf viewers and also in prints.