Hey folks, here's how to handle both Night Light command-line tasks in Windows 10:

If you just want to turn on Night Light using your existing scheduled settings, you can modify the relevant registry entry via Command Prompt or PowerShell. Here's the Command Prompt command:

reg add HKCU\Software\Microsoft\Windows\CurrentVersion\CloudStore\Store\Cache\DefaultAccount\$windows.data.bluelightreduction.bluelightreductionstate\Current /v Data /t REG_BINARY /d 01000000010000000000000000000000 /f

This sets Night Light to enabled. To turn it off later, replace the binary value with 01000000000000000000000000000000.

If you prefer PowerShell, use this:

Set-ItemProperty -Path "HKCU:\Software\Microsoft\Windows\CurrentVersion\CloudStore\Store\Cache\DefaultAccount\$windows.data.bluelightreduction.bluelightreductionstate\Current" -Name Data -Value ([byte[]](0x01,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00)) -Type Binary

To make the change take effect immediately, restart File Explorer:

taskkill /f /im explorer.exe && start explorer.exe

To activate Night Light instantly (bypassing scheduled times) and set a custom color temperature, you'll modify a specific registry entry that controls the advanced Night Light settings.

Step 1: Enable instant Night Light #

Run this Command Prompt command to turn on instant mode (this ignores your scheduled on/off times and keeps Night Light active right away):

reg add HKCU\Software\Microsoft\Windows\CurrentVersion\CloudStore\Store\Cache\DefaultAccount\$windows.data.bluelightreduction.settings\Current /v Data /t REG_BINARY /d 010000000100000000000000000100000064000000 /f

Step 2: Adjust color temperature #

The last 4 bytes in the binary value (64000000 in the command above) control the temperature. This is a little-endian 32-bit integer:

• 00000000 = 6500K (default, coolest)
• 64000000 = 2200K (warmest)

To set a custom temperature:

1. Calculate the value using: Value = ((6500 - Target_Kelvin) / (6500 - 2200)) * 100
2. Round to the nearest integer, then convert it to a little-endian 4-byte hex string.

For example, to set 4000K:

• Calculation: ((6500 - 4000)/4300)*100 ≈ 58
• Little-endian hex for 58: 3A000000
• Updated command:

reg add HKCU\Software\Microsoft\Windows\CurrentVersion\CloudStore\Store\Cache\DefaultAccount\$windows.data.bluelightreduction.settings\Current /v Data /t REG_BINARY /d 01000000010000000000000000010000003A000000 /f

Step 3: Apply changes #

Restart File Explorer to see the changes immediately:

taskkill /f /im explorer.exe && start explorer.exe

内容的提问来源于stack exchange，提问作者elig