How to force to use Gamma Space instead of Linear Space?

Hello,

How to force to use Gamma Space instead of Linear Space?
I am working on an application targeting for iPhone5~latest iPhone and since unity 5.5 uses linear space with the devices that supports it iPhone5 and iPhone6+ seems to have different colors with post image effects. I want to force unity build to use Gamma space only for my game.

To specify a gamma or linear workflow, go to Edit > Project Settings > Player and open Player Settings. Go to Other Settings > Rendering and change the Color Space to Linear or Gamma, depending on your preference.