I'd like to find a simple (& preferably free) way to invert the colors of any pdf file- ie light text (white or yellow) on black background. I find I quickly get headaches if i'm reading black on white background. I want to find a way to "convert" the files..i do not want to ues the 'accesibility-> change color' option in adobe. The reason is: 1) it doesn't always work (sometimes text changes but not the background) 2) i want to use grahl pdf annotator to highlight/make notes & it does not have a feature to change the pdf colors (ie once in grahl, it's back to black on white so i need to convert the actual file). A solution I've tried so far, is to convert the pdf into image files using PDFill, then batch converting the images into negatives using fastone image viewer, then converting back to pdf using PDFill. It works well, except it's a little tedious & i lose the ability to search the pdf. I think adding an OCR step would enable me to search the pdf again, but i need learn a bit more about OCR & i'm concerned that after OCR, it won't be as reliable as the original pdf's search ability. Is there a way or program to do these steps at once? Anyone else have experience inverting/converting the colors of text of pdfs? thanks!