How to use Dark Mode in Microsoft Outlook
How do you turn on Dark Mode in Outlook?
Dark Mode is not a theme
Microsoft designed Dark Mode with an analogy that the way most people expect themes to work is different from the way the mode works. There are plans to have a dark experience for all available themes in the future, but the primary focus has been put on having something separate. Outlook’s Dark Mode only supports the default blue theme currently.
One of the most crucial principles we had when designing Dark Mode was to minimize the amount of eye strain that people felt. Many email clients on the web today advertise a dark theme, but we learned from interviews with others and our own usage that having the reading pane be on-light while the rest of the interface was left on-dark often made the experience worse than if the full screen were left on-light.