PowerPoint and OpenOffice support eps files, but changing the color of the icons isn´t possible with eps files. If you export your icon as *.emf (Enhanced Metafile) you are able to change the colors with PowerPoint, but you lose all your curves, if you look closely on your icon.
It took me some trials to convert the icons made with Illustrator to make them editable with PowerPoint. It takes a few steps, but it works. Now it´s possible to change the color of the icons with PowerPoint and OpenOffice.