Rendered VR frame looks very washed out with 5.4.1 (Oculus)

Hi,

I was using the VR mode successfully in Unity 5.3.5 till last night. The headtracking, detection and rendering all worked fine. After switching to 5.4.1 last night the colors appear completely washed out in the VR rendering. They're fine if "Virtual Reality Supported" is disabled, and are fine in the actual scene, but the actual frame drawn to the Oculus screen is washed out.

Screenshots to compare: http://imgur.com/a/rIMNk

I'm trying out the intermediate versions (5.3.6...

Rendered VR frame looks very washed out with 5.4.1 (Oculus)