Change Widget Task icons in the home screen.
Only Widgets that have a downloaded icon can have it switched to a new set.
The New field specifies the new icon set.
If no Old set is specified, all icons are changed to the New set, otherwise only icons that currently have an icon of the Old set are changed.
Warning: for Tasker icon sets, each icon is guaranteed to exist in each set. For user-installed icons, that may not be the case.