Chameleon
Chameleon mod allows you to personalize the application icon in Dock on macOS computers for Minecraft clients version 1.19 and above. Starting from version 3.2.0, experimental support for Windows operating system has also been implemented.
For users of macOS Big Sur and newer versions, a set of nine different icons is available that can be used to change the game's appearance.

You can change the icon in two ways: using the client command /chameleon <icon name> or through the Mod Menu interface. For advanced users, there is an option to add custom icons through custom resource packs.

Important Requirements
For the mod to work correctly, you need to install fabric-api. Also make sure you are using Java version 17 or higher.