For startup defaults, the icon may be red or grey. The red icon indicates that the default has been changed by a user and now differs from the ArtiosCAD internal default.
If a user changes a default, the icon will turn red. Note however, that some of the icons may already be red after installation. The ArtiosCAD application has a hard-coded internal value that it uses to seed the default with. If the default is red after installation, this means the defaults file that ships with ArtiosCAD differs from its hard-coded value. This means that somewhere along the way, Esko decided to change the shipping default to something that may have been more practical in more common cases.
If the user deletes a startup default, the net effect is that the defaults revert to the hard-coded internal value the next time the defaults dialog is displayed.
For Design Defaults, the icon is different, but the red and grey meaning is the same.