If you customize the browser icon for an iFeature (.ide) file, the new icon will appear in the browser when you place the iFeature in a part file.
Previously placed instances of the same iFeature do not update with the new icon appearance.
Every time you use the iFeature, its new icon is used. Even if you edit the iFeature, the icon retains its custom appearance.
Open. Browse to the folder where iFeatures are located. Select an iFeature, and then click Open.
iFeature panel
Change Icon.