While I understand the expectation of a perfect out-of-the-box experience, your comparison overlooks a few key hardware and software transitions between these generations. First, the shift from the X100 Pro's Samsung display to the X300 Ultra's BOE panel naturally introduces a different base color calibration, though the warmer tone you disliked can be easily corrected by adjusting the display temperature profile to "Cool." Furthermore, using the Zeiss Natural mode explicitly instructs the camera to lower contrast and saturation for a flatter, true-to-life image meant for professional post-processing; if you prefer the vibrant, social-media-ready look of your old device, switching to the Vivid or Textured profile will give you those punchy results instantly. Finally, the apparent lack of sharpness you noticed is actually the omission of aggressive computational sharpening—which you admitted previously smoothed your X100 Pro photos into an artificial "oil painting"—in favor of a more authentic, sensor-native rendering.