The Brightness factor and 3D presentations are almost a perfect pair of arch-enemies.
While there’s an eye-popping factor to a proper third dimensional image, there’s the risk of the brightness being dampened by the 3D glasses you’re required to wear.
In terms of Smallfoot’s presentation, that washed-out coloring isn’t a total deal-breaker, but it certainly is noticeable when you take your glasses off.
Your mileage may further vary with this factor though, as your local theater may not always keep their projectors properly calibrated or maintained between 2D and 3D shows; yet, even with a pretty bright showing, Smallfoot was a bit darker than it should have been.