Supported Unity 2019.4+

1. Open context menu: Window > Package Manager
2. Click the ➕▾ in the top left and choose Add Package from git URL
3. Enter https://github.com/ErnSur/unity-editor-icons.git and press Add

You can change script icon using icons file id

1. Open *.cs.meta in Text Editor
2. Modify line icon: {instanceID: 0} to icon: {fileID: <FILE ID>, guid: 0000000000000000d000000000000000, type: 0}
3. Save and focus Unity Editor

You can load Icons below by using EditorGUIUtility.IconContent with the icon name. e.g., var content = EditorGUIUtility.IconContent("console.warnicon");

Click on an Icon to get its details.

Icons from Unity 2021.3.0f1