There is a rich, glorious color palette on display in The Incredibles 2, and as such, the 3D presentation has a potential to dim that color with the addition of those black and grey lenses you don to watch the film.
It’s not always the conversion team’s fault that a film such as this gets washed out, as it really does depend on how well your theater calibrates their equipment between showings and/or switches between 2D and 3D viewings of the film you’re about to enjoy.
With those caveats in mind, Incredibles 2 still has a fair amount of washed out colors, and even some issues with scenes portrayed in slight and almost total darkness, leaving some moments hard to watch for the audience behind the 3D glasses.