Hi my iphone 7 plus is sepia all of a sudden

Hi

You appear to be referring to Night Shift mode, which automatically adjusts the colour of your display after sunset, making the display easier on your eyes and returns it to the regular settings in the morning.

To disable or adjust the settings for the feature:

• Swipe up on the display to open Control Centre > tap the Night Shift icon (shaded sun) to turn the mode on or off.
• Go to: Settings > Display & Brightness > Night Shift - including to schedule the setting and/or adjust colour temperature.

More information:

Adjust the display settings on your iPhone, iPad, or iPod touch - Apple Support

Try to reset your device. This won't delete your data stored on this device.

• Press and hold the Sleep/Wake button
• Press and hold on the Home button
• Keep holding both buttons until the display turns off and back on with Apple logo on it.

Alternatively, you may go to Settings - General - Reset - Reset All Settings

If this does not help, restore your device to factory settings. Note that this will erase the data from your device.

Take a look this Apple Support article: Use iTunes to restore your iPhone, iPad, or iPod to factory settings - Apple Support.

Luco,

Just a quick note for you, that you may not have been aware of, that performing a reset, or what is now called a forced restart for the iPhone 7 is done differently than other devices. Because of the home button change, to perform a reset on the iPhone 7 one holds the sleep/wake and the volume down button, instead of the home button. Thought you might like to know that if you are dealing with a poster using an iPhone 7. 🙂

Note that Apple advises that you should not force restart your iPhone unless it is unresponsive and cannot be restarted normally:

Restart your iPhone, iPad, or iPod touch - Apple Support

Also, neither restarting nor force restarting your iPhone would have any effect on Night Shift mode.

This indeed sounds like an overly aggressive Night Shift. Either turn it off or reduce its level of adjustment.

It is intended to reduce the amount of blue-tinted light it sends at night, which is supposed to impede your good night's sleep. I'm thinking that Herr Trump either does not do iPhones or has his with NightShift definitely turned OFF, hence the 3 AM tweet storms.