Double Your Icon Set

I use an icon set that has beautiful, full color icons (http://everaldo.com/crystal_project). However, sometimes a grayscale version of an icon can be used as a subtle control, or to allow other icons and page elements to appear more prominently.

ImageMagick can be used to convert full color icons into beautiful greyscale icons, very quickly.

convert ok.png -colorspace Gray grey-ok.png

Original image: Color OK

Greyscale image: Greyscale OK