First pic is with the colour filter installed, 2nd pic is without it (like you'd get with the cardboard version).
With the colour filter, it makes a massive difference to the contrast, there is no more blue glow from the LCD, it goes completely black. The main issue I have with it is that the colour filter restricts the view quite heavily. You can see the games just fine, but when you're in the main menu you do have to move your head around to see the menu icons.
The difference is extremely noticable in real life, night and day for sure.
by Xenith332