The web site http://www.beelinereader.com/ provides a chrome browser extension which colorizes paragraphs so that moving your eyes from one line to the next is much quicker than with just black text.
See http://www.calpoly.edu/~mstankus/beeline-paragraph.png for a graphic which should make this clear.
Can this be done in LaTeX in a semi-automatic or automatic way?
Mark
Google Spritz. There is a commercial and an open source implementation. For most things online, they provide a bookmarklet.
– masfenix Mar 01 '15 at 23:25beelineinto the site search box:-) http://tex.stackexchange.com/a/131919/1090 – David Carlisle Mar 01 '15 at 23:37