Here are the details of how to turn off Blue Light on your iPhone. You can’t completely switch it off, but you can block it out within Night Shift settings.

Turning Off Blue Light on iPhone
In warm temperatures, Apple’s Night Shift mode automatically changes its screen colour. You can turn on the Night Shift mode to adjust it in two ways.
- Control Centre
By using this method Night shift can turn on from sunset to sunrise.
- Display And Brightness Settings Tab
You can access Night Shift from the Settings Menu to customize this option.
Turning On Night Shift With Control Center
In the Brightness panel from the Control Center, you can turn off Blue Light quickly.
Open Control Center by swiping down from the top right corner of the display>Tap and hold the Brightness icon>Tap Night Shift icon to turn on
Turning On Night Shift in Settings
Open Night Shift option from the Settings to adjust the Blue Light on your iPhone based on a schedule. First open the Settings, then scroll down to Display and Brightness. Tap the option Night Shift. Then you have to choose the option Manually Enable Until Tomorrow to turn off Blue Light till the sunrise tomorrow.
There is an alternative option. You can use another option to turn it on. For this method, you have to choose the toggle next to Schedule and choose the From / To tab to customize to start and end times.

How Can You Remove Blue Light in Night Shift?
This option can just adjust the color temperature of your screen. It doesn’t remove the Blue Light. It can reduce the amount of Blue Light you see.
If you just want to adjust the amount of Blue color, you can opt out of this option in your iPhone’s temperature slider to More Warm. the slider you can find under the Settings option, then Tap the Display and Brightness. Then choose Night shift then Color Temperature.
These are the methods you can go for to turn off the Blue Light.