>>38542113Because the director knows what color theory is.
The entire scene is warm colored, except the background and tertiary objects like the desk, to draw your attention to the center of the frame.
The evolution effect is cool colored and brightly lit, to easily identify the action in the scene.
If it was any other eeveelution, it would clash too harshly with the rest of the color in the scene, confusing the point of interest.
The main purpose of the scene is to draw attention to the act of evolution, not to the Eevee evo itself.
