If you have recently purchased an iPhone 18 Pro and upgraded from an iPhone 15 Pro, and you are noticing a significant difference in display quality—such as the screen appearing whiter, less vibrant, or noticeably less colorful compared with another iPhone 18 Pro or 18 Pro Max—I would not rely solely on opinions or suggestions from an online forum.
If I were in your position, I would visit the nearest Apple Store or an Apple Authorized Service Provider as soon as possible and have the display examined alongside another iPhone 18 Pro. Since the phone is new, it is worth establishing whether what you are seeing is simply a difference in display calibration or settings, or whether there could be an actual hardware or display-panel issue.
You can also ask the Apple representative to compare your phone directly with a known-good iPhone 18 Pro/18 Pro Max under the same lighting and display settings. This makes the comparison much more meaningful than relying on photographs or descriptions posted online.
A new iPhone is a significant investment, and if something about its display looks noticeably abnormal to you, getting a first-hand assessment from Apple should be the priority. Forum members can certainly offer useful suggestions, but they cannot physically inspect your device or determine whether the panel is operating within Apple's specifications.
Don't spend days trying random settings and waiting for someone online to provide a definitive answer. Take the new iPhone to Apple, get the display checked, and let them clarify the situation while the device is still new and within its applicable return, replacement, or warranty period.
