Classic Google Icons is an extension that reverts the icons for Google apps, such as Gmail, Mail, and Drive, to their pre-2020 Material Design look.
- Chrome: https://chrome.google.com/webstore/detail/classic-google-icons/gdiohdhgkjainohnfhofjoebohnfknnm
- Firefox: https://addons.mozilla.org/en-US/firefox/addon/classic-google-icons/
To load a dev version into your browser, just select the extension folder (or manifest.json inside it for Firefox) and you're ready to go.
Top level folders
- extension: Contains the extension files. This is probably what you are looking for.
- imageLibrary: A library of Google icons that are stored in case they need to be accessed for the extension. This is not included in the final product.
- promo: A library of assets related to Classic Google Icons on the Chrome and Mozilla web stores. This is not included in the final product.