True Tone

Hi bigger68,

We see you have a question about True Tone. Your iPhone and True Tone should function the same after battery replacement when performed at an Apple Store or Apple Authorized Service Provider with genuine Apple parts. This link has some further information About genuine iPhone displays - Apple Support (AL)

"If a service provider uses nongenuine display parts, the following might also occur:

Multi-Touch issues

• Multi-Touch might not respond on parts of the screen
• Degraded Multi-Touch performance, such as missed screen touches or touches not registering in the right location
• Touches might unexpectedly register during a phone call
• Display might not turn off during phone calls
• Accidental edge or palm touches might register

Display brightness and color issues

• True Tone display doesn't function correctly
• Lost or degraded function of the ambient light sensor, causing the screen to dim or brighten incorrectly
• Incorrect display color calibration, such as the display to appearing too yellow or blue
• Display isn't uniformly bright
• Lower maximum brightness
• Unintentional battery drain"

Kind regards.