Stilly -

I haven't heard a recent update on it, but the usual advice on using newpaper in your compost was that the plain text was okay, but you should avoid putting the fancy colored stuff in. The black inks were mostly carbon pigment, but even fairly recently many of the colored inks contained stuff that could be toxic to the "critters" that work the compost for you. It wasn't that it was "poison," exactly, but the colored inks all had metallic components (Chromium, Cadmium, and the like) that would kill your red wigglers - and maybe some of the smaller worker bugs.

There's probably more recent info now, as it's been quite a few years since I used newsprint in the fishin' worm brooder.

John