If ‘save into document=true’ in the advanced settings, no highlight can be undone once it is saved. If ‘save into document=false’, the information related to the location of the highlights is saved into a separate file which can be modified. There are two different ways of erasing highlights in this case as far as I know:
- Find the exact entry in the newly created file associated with the location of the highlight and erase it; this can be ridiculous if you’ve done a lot of highlights already.
- If the highlights were done by text highlight (not area highlight done by ‘ctrl+mouse then A’), then reapplying the highlight to the exact space will undo it. The color should be matched in this case. This method can be used even if ‘save into document=true’ IF the highlights are not saved yet.
I don’t now any simple way of removing area highlights other than searching the whole text file See the previous thread for more information.