Why iPhone 13 Pro sierra blue color display different colors under different lighting like night light, day light, blue light,

Hello Wicky0926,

If the display appears to look different in different lighting conditions, it may be related to display settings, such as Night Shift or Auto-Brightness.

Please check out this link, which explains how to review and manage those settings, and display brightness and color, which may help: Adjust the screen brightness and color on iPhone

Turn Night Shift on or off

You can turn on Night Shift manually, which is helpful when you’re in a darkened room during the day.

Open Control Center, touch and hold , then tap .

Thanks!