Dim background effect in Unity's UGUI system

I need code for a background dimming effect for UGUI items. ## Specs - Specify which UI elements need to be excluded from being dimmed by the dark background - Must work with all types of UI elements (buttons, panels, etc.) - Must work for non-standard UI elements (e.g. circles, ovals, etc.) - Work with dynamic UI elements (the ones that change size and position) - Work with all Canvas modes (Overlay, Camera, World) - Work with all Camera modes - Lightweight and fast to render (no lag) - Preferably easy to setup - Be able to control the color and transparency of the dimmed background I have screenshots to show you what I mean. ## Requirements - Must work with Unity 2019.4 and above - Do not modify transform ordering to achieve this result, it's not appropriate for what I need - Controllable via C# script - Must not depend on third-party assets to work - If your work needs to be dependent on an open-source framework, let me know - Must work cross-platform - Compatible with render pipelines. Can have three separate implementations to work for each solution if that’s the only way. Preferably must co-exist together in a single project - Built-in render pipeline - Universal render pipeline - High Definition render pipeline ## Expected deliverable format - A .unitypackage that contains all required code as well as an example scene - Code (be it GLSL or C#) must be reasonably commented and method/variable names must be clear