Beamer user guide says at p140:
Example: For a more interesting usage of the ⟨default overlay specification⟩, consider the following usage:
This will always paint the most recently added part of the graphic in red (assuming you do not use special colors in the graphic itself).
However, a simple test with gra.pdf files (saved from inkscape) doesn't seem to be rendered red at each overlay. The pdf files contain only black lines. No matter what I try, seems every color is a "special color", and beamer does not correctly alert/highlight elements in the pdfs, like in this (correct) example using xfig:
What's your experience on this issue? Can I correctly alert pdfs produced by tools like inkscape?
I do not have a minimal example right now, but may supply one a while later. Thanks for any help/hint!