This is a really petty complaint, but in macOS, a file will assume the icon set for it by the default application set to open that file, but on my Mac certain file types, the icon seems to be generated on the fly to a very basic generic icon. The only file types that this happens with are files that Quicklook can view.
I have doubled checked the default application set to open HTML files, but it's not just HTML files. It is any file that can be previewed with Quicklook.
Another Example With What A PHP File Icon Should Display As VS. What It Actually Displays As:
I believe these icons are being generated on the fly because it is the same generic looking icon, but the file extension is written at the bottom of the icon. Second, it only happens with files that can be previewed with Quicklook. Third, if the OS doesn't seem to have it cached, or I haven't opened the file for a while it will display the correct icon for a split second and then switch over to the generic icon. Lastly, I did find some strange icons that looked like they were the corners for that icon when digging around in /Library/Core Services ( It was for sure in the /Library/ folder, but I can't 100% remember if it was inside one of the bundle file's resources folder ). It looks like Quicklook does generate the preference panes icon on the fly, found in /Library/Quicklook/StandardBundles.qlgenerator/Contents/Resources . By looking at the plist located here: and as you can see the gear icons here:
I really want to stop macOS from generating these icons. I just want my system to display the correct icons that are associated with the file type. I don't care for the generic icon, and although it does not make any difference it bothers me, and I would be interested in how this actually works.