Dark theme or Windows 10 High Contrast mode is mostly used for reading purpose at night or in low light so that the screen light does not affect your eyes. So in Windows, there is an option to change Windows 10 theme into high contrast mode.
By default, it is set to a Light theme. You can change it into a dark theme. You can also change Windows 10 style for a particular app into dark mode. Let us see How to turn high contrast mode on or off in Windows 10.
How to turn off high contrast mode Windows 10
First, you need to Open Settings in Windows 10 by either using the shortcut Windows + I or Click Windows logo and choose Settings
Click Personalization icon
On the left hand side Select Colors
Scroll down Choose default app mode to Light and default Windows mode to Light to disable dark mode.
How to turn off high contrast mode for both Settings and apps
Most of you facing problems with not able to enable dark theme because having an old version of Windows 10 then you can go for either High Contrast Settings or Update Windows 10 to use reader mode. High Contrast also works like Windows dark theme not only in Settings but also Apps.
How to turn high Contrast mode ON or OFF in Windows 10
First, you need to Open Settings by either using the shortcut Windows + I or click the Windows logo and choose Settings.
Click Personalization icon
On the left hand side Select Colors
Right hand side you will see High Contrast Settings under Related Settings
Open High Contrast Settings > Turn On high contrast
In most cases dark themes in file explorer not working in Windows 10. By enabling this High Contrast Mode Settings, File Explorer also will be set as a dark mode.
How to enable dark mode for Microsoft Office
You can also set up Microsoft Office in dark mode. Follow below steps
Open Word, Excel which you want to enable dark
Click File on top right corner then, Go to Options
Open General Tab > Color Scheme > Select  Black
Press Ok to save your Settings.
How to manage Firewall settings in Windows 10
