All the objects in any project flash in brown-green-yellow colors.
Even if I try to create a new project from template, I have the same result.
All the projects which opened good in 4.7 version are brown now.
I use Ubuntu 14.04. UE was built from branch 4.8 https://github.com/EpicGames/UnrealEngine.git
Had the same result when built from release branch. Also, used 4.8.3-release tag, and had the same result.
Here is the same project being opened in 4.7 version: