macfoldericonformat

IntheFinderonyourMac,changetheiconforanyfileorfolderusingyourownpictures,iconsfromtheweb,oriconsfromanotherfileorfolder.

參考資訊如下
Change icons for files or folders on Mac

In the Finder on your Mac, change the icon for any file or folder using your own pictures, icons from the web, or icons from another file or folder.