How to install True Tone on iPhone Xs?

You cannot fix it. Once the screen was replaced by a third party with a non-authentic Apple screen, True Tone will never work. And you can't take your phone to Apple and ask them put an authentic screen on your phone, because they won't touch your phone.

So, you live with a phone in which True Tone is not a feature you have access to.

That would happen when the screen on your phone was replaced with one which is not an authentic Apple screen. If that is correct, you will not have True Tone and it can't be added.

If it is a 3rd party screen you can make a Genius Bar appointment and ask if they will let you pay to have it replaced with a genuine screen.

There is nothing you can do. Once an iPhone has had parts installed by a 3rd party, certain features won't work, like True Tone. And Apple won't touch the phone since its been tampered with, so you live with a phone which will never have True Tone enabled.

Hello,

See this:

Adjust the brightness and color temperature on your iPhone, iPad, or iPod touch - Apple Support

Good luck.

True Tone is not showing on my iPhone X. I tried checking the settings on my iPhone but I didn’t see the True Tone option under “Display & Brightness”. What do I do?

I’ve had the screen replaced and I bought the iPhone from an Apple Authorized Reseller but the True Tone doesn’t show

So what do I do now?

So how do I fix it

Did you buy this iPhone new directly from Apple or an Apple Authorized Reseller? Have you had the screen replaced?