I have just started using a bluetooth page tuner when using PDFs as I can't always time the changes well automatically. I have set the page to advance half a page at a time. It would be a cool feature if the half page just moved from had a filter applied to it, perhaps a colour screen, so that the eye moves easily to the next line.

What exactly should be colored when? And why not use timed lyrics? You don't need to set a timestamp on each line. Put a timestamp on each half page of information. That will highlight the whole block of text within a timestamp.

    peter It's more for when using PDFs rather than lyrics. I do use timers for lyrics and chord sheets as you suggest but when trying to follow a solo on a PDF such as Santana's Smooth, i need to look away to the neck in some places and if I don't look back at the right place, it's easy to mess up. I just wonder if a scrolled PDF could have the previous part 'greyed' or something so that the eye doesn't go back to the wrong line, especially when it has moved half a page. I'll try to make a screenshot later in the week when I'm at home to show you what I mean.

      Editing features on pdfs are limited with the standard viewer that ST3 uses. Highlighting a document is not possible to my knowledge.