Question
What do the defaults colors in ArtiosCAD mean?
Answer
For startup defaults, or any fixed set of defaults which the user can only change values for but not add new definitions to (ie, New > Folder/Data is disabled), the colored icon indicates that the default has been changed by a user and now differs from the ArtiosCAD internal default. If the icon is grey, it was never changed.

If a user changes a default, the icon will be colored. Note however, that some of the icons may already be colored 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, or any fixed set of defaults which the user can only change values for but not add to, the icon is different, but the red and grey meaning is the same.

If the user drags a fixed default from Shared to User (or Location for Enterprise), for example, Startup Defaults > 3D Quick Views was dragged over to User. Note that 3D Rendering Options was changed on the Shared side but comes over to the User side as grey. This means the User 3D Rendering Options technically not been created and serves more as a placeholder and will inherit values from the Shared side... until the ArtiosCAD designer changes values on the User side.

Other defaults are called Table defaults, by which users can create Folders and new configurations/data, like Outputs, Calculated text, parameter sets etc (ie, New > Folder/Data is enabled). These do not follow the override scheme described above and instead are joined together in a list when presented to the user.