title: How do I know if PDF pages are color or black-and-white?
body: <p>Given a set of PDF files among which some pages are color and the remaining are black &amp; white, is there any program to find out among the given pages which are color and which are black &amp; white?  This would be useful, for instance, in printing out a thesis, and only spending extra to print the color pages.  Bonus points for someone who takes into account double sided printing, and sends an appropriate black and white page to the color printer if it is are followed by a color page on the opposite side.</p>