Windows 10 allows you to enable Night Light mode (previously known as Blue Light) to reduce eye strain. When enabled, it makes the screen color gamma more comfortable for your eyes at night by reducing blue light. Colors become more warm and the backlight will be dimmed, so eye fatigue will be less. Some users are faced with a strange issue where the Night Light options are grayed out in the Settings app. Here is a quick workaround to resolve this issue.