Custom Collection Icons in the Outliner

Right now, collection icons in Blender are hard-coded — the only customization is changing their color. In big projects, this makes the Outliner harder to navigate, because every collection looks almost the same.

In tools like Cinema 4D, you can choose different icons for collections and objects. This small change makes large hierarchies much clearer and easier to work with.

My idea is to give users the ability to:

Pick from a set of icons (folder, star, cube, camera, light, etc.).

Optionally use custom icons for even more clarity.

This would make the Outliner a bit more readable and user-friendly, especially for big productions with many collections and objects.