Microsoft confirms Windows 11 folder icon changes are intentional

Windows 11 changes how folder customizations work, and what looks like a bug is actually a security upgrade.
XDA Developers on MSN

Microsoft just broke some custom folder icons, and it's deliberate

Fortunately, there's an easy fix.
The Droid Guy

How To Set Custom Icons For Your Android Apps Tutorial

Use a Square Image with a Transparent Background: For optimal results, use a square image with a transparent background. You can find such images online or create them using photo editing tools.
Android Authority

Google is working on AI-powered custom icon themes for your Pixel phone

Google may be working on new AI-powered icon customization features for Pixel phones. This feature could solve the inconsistent look of the current “Themed icons” feature, which many apps still do not ...
MacStories

Home Screen Icon Creator: A Shortcut to Create Custom Icons for Apps, Contacts, Solid Colors, and More

Update: Thanks to MacStories reader Thomas, I was able to remove the need to upload image assets to Dropbox. The shortcut is now much faster to run (takes about 5 seconds instead of 20) and doesn’t ...