Hi there!
I started a new Unity 5.5 project with the HoloLens, which I started testing today.
I noticed that the skybox background is always showing up on the HoloLens and this way I’m kind of looking through a whit fog.
My target is to simply show holograms in the room whithout any kind of background.
I’ve also tried to remove the skybox, which leads to a blue background, which is not even better.
You need to change the camera settings for the main camera to properly do this. The Clear Flags needs to be set to Solid Color and the Background to Black, i.e. the RGBA to 0, 0, 0, 0. The trick is that black is transparent on the HoloLens.