Convert images to cross stitch patterns: choose the number of colors to use and the final pattern size; edit your pattern (save and restore your work); save your pattern as a pdf.
This closly matches the color of the floss here:
http://yarntree.com/075dmccolors.pdf which is photos of the floss itself so it
should be pretty accurate.
Updated with both more +36 colors and colors better mathing the dmc floss. Colors are generated from this .xml file that is part of kxstitch: http://sourceforge.net/p/kxstitch/kxstitch/ci/83556a8b36bb6eeea66913206f394795eab02c6c/tree/schemes/dmc.xml
This closly matches the color of the floss here: http://yarntree.com/075dmccolors.pdf which is photos of the floss itself so it should be pretty accurate.