In the tradition of Neo-Brutalist design, the principle of Surprise and Delight demands that the user be constantly astonished and charmed by the experience. Abandon All Hope, a related but distinct principle, is often at odds with this one.
To achieve this, one might use Flashy Animations or Colorful Noise to create an experience that is both jarring and delightful.
Or, of course, one might simply Just Add More Brighter Colors.