Steps:
1. Open attached project
2. Load Level2 scene
3. Untoggle "Scene Light" and "Skybox" toggles in scene view toolbar
4. Select "EnvironmentalHazards -> DestructibleBox (first one) prefab
5. Double-click on it to bring it into view
6. Search for "des" in the Hierarchy
==> All the objects are greyed out except those which name is started from "des"
7. Toggle "Scene Light" and "Skybox" toggles in the scene view toolbar
==> Scene view has extra purple color and destructable box prefab instance is much more brighter

Expected:
Greyed out objects should stay greyed without additional color. And if this is possbile the brightness of the scene should remain as before.

To be clear, the issue is not that the post effects are present. They should be. The issue is that they’re applied after the scene view filter instead of the scene view filter being the last to be applied. So e.g. the scene view gray-out effect, it should be the last thing applied so the end result is gray regardless of color-grading for example. Instead of the color-grading making the gray-out effect being no longer gray.

Note: New InContext editing prefab mode feature relies on the Grey out effect and also affected by this behaviour.
Please find attached movie for details.

Also repro in 2018.4.16f1 (e6e9ca02b32a)