Scene Color won’t work with sprites in a transparency filled scene b/c this node uses the Camera Opaque Texture.
The closest thing is in the the 2D Renderer, which can be set up to use _CameraSortingLayerTexture. It’s not quite the same as SceneColor but similar.
Look for the Heat Haze Overlay scene. It essentially lets you take a snapshot of the current state of the transparent scene at a particular point. However, it’s fairly limited.
Dev discusses setup here: Unity 2DRenderer Heat Distortion shown in the Unity GDC Showcase 2021 not working (note this post is a little old so the github is probably more accurate if something seems off). See also: 2D renderer -> _CameraSortingLayerTexture · Issue #1 · gamedevserj/Shader-Graph-Experiments · GitHub