In certain situations, it is necessary to generate slightly modified versions of icons to indicate different states, for example:
Standard icons may have up to 15 image formats (3 color depths * 5 sizes). Applying the desired effect on each image manually would be a waste of your time.
RealWorld Icon Editor allows you to prepare commands that would apply effects on every image of an icon and it comes with the basic effects pre-configured. Commands in Icon->Filter all images menu cover the basic scenarios. You can generate grayscale images by reducing saturation to 0 using the Color adjustments filer.
To apply other filters on all images at once, you'll need to learn to reconfigure the Window Layout. The information in the following section will be useful as well.
A batch operation for application of state effect is not one of the built-in ones, but it is easy to configure:
Name and operation fields at the top of the window allow you to specify user friendly name (in multi-language format) and the actual operation performed. Note that the operation is set to the Sequence operation by default. This is desirable, because after the effect is applied in the first step, the modified file is saved to the destination folder in the second step. To create a color desaturation filter, do the following:
Click OK and your new batch operation is ready to use (drag and drop icon files or folders on the application window to process them). You can also save it to a file and share it with co-workers or archive it.