This seems like a bug, and I seem to track down the source. I had a project from 5.1.x and updated to 5.2.0f2 and noticed all my lights and colliders have random colours for their ranges. I thought maybe it was an editor script so I deleted everything in the project one by one until I had no files at all left. It was still happening with a clean new scene and after editor restarts. Is this a new "feature" or a bug somewhere? While it still happens after restart but a clean new project does not show this behaviour. I'm using Gamma (never was in linear) color space, and have MSAA disabled, but tried other settings all the way to fastest and still have that issue.