1. Avoid Pure Black
Pure black may increase the eye strain for the viewer. Dark Grey on the other end is easier on eyes and can be used express a wider range of color, elevation, and depth.
2. Use Desaturated Color
Less saturated color makes the design more accessible by improving the legibility and reducing the visual vibration.
3. Avoid pure white for text
When light text appears on dark backgroundsit should use the following opacity levels:
4. Lighter Surface = Higher Elevation
The higher a surface’s elevation (raising it closer to an implied light source), the lighter that surface becomes.That lightness is expressed through the application of a semi-transparent overlay.
5. Maintain the emotional aspect of design
When converting from an existing light theme to a dark theme one has to keep in mind the visual emotion the brand is evoking by adjusting the color contrast etc. A dark mode does not (always) have to be derived from the existing light theme.
6. Allow users to switch from regular to the dark mode
You should not take away the controls from the user to turn on or off the dark theme. Users should be able to opt into a mode manually, based on their own needs.
7. Use Accessible color contrast
Ensure that your content remains comfortably legible in Dark Mode. Dark theme surfaces must be dark enough to display white text. Google Material Design recommends using a contrast level of at least 15.8:1 between text and the background.