Dark will fail just like the new 2002 cartoon. The bright colors are a big part of the attraction of the action figures. Look how successful the classics line is because its sticking to the original.
Now make it Colorful and a little more serious story, it can work. It worked great for spider-man 1 & 2. I hate part 3 btw
Stick to the story and classics line visuals and just make it a good story, maybe start the movie with the queen landing on eternia from earth, ok now im going to far but colorful way better