This week Slack released a dark mode feature in their latest iOS and Android update and users are delighted. In dark mode or night mode the interface color palette gets a lot darker with using black as a background color and white text (compared to white background and black text).
There are many benefits of using dark mode, especially when using your device at night. Humans are diurnal, and our vision works best during the day when its bright outside. However, using bright displays at night can cause eye fatigue and headaches. Next to that, your circadian rhythm (your biological clock) is affected by the blue light of the display. Using dark mode may therefore increase your sleep quality.
Another upside of dark mode is that it uses less power and therefore goes easy on your energy bill and increases battery life. Next, the dark backgrounds keep your device cooler compared to bright interfaces.
The dark side of dark mode
Back in 2017, scientists from University of Würzburg presented some interesting findings on dark user interfaces that exceed the commonly looked-at issues of aesthetics or legibility. In a first of its kind study they found out, that the background color of a chat user interface influences the perceived valence of the chat message. Dark mode = dark mood?
To test their hypothesis, the researchers divided 67 participants into two experimental groups. Every participant was tasked to rate more than 200 chat messages in terms of their sentiment (either positive, neutral or negative). For one group, the background color of the user interface was black, the other group encountered a white version of the user interface. As a reference, they used an automated sentiment analysis and an expert evaluator group.
Their findings reveal that the ratings of the chat messages were significantly more negative for participants using the black theme compared to the bright theme. With that, they are the first study to prove an emotional and semantic effect of background color.
Still, the study has some limitations such as a small sample size, only three categories for sentiment, lack of generalizability of used chat environment, lack of qualitative information gathering to only name a few. Nevertheless, it’s a super interesting piece of research and I’m looking forward to further investigations into emotional effects of dark mode usage.
Source: Löffler D., Giron L., Hurtienne J. (2017) Night Mode, Dark Thoughts: Background Color Influences the Perceived Sentiment of Chat Messages. In: Bernhaupt R., Dalvi G., Joshi A., K. Balkrishan D., O’Neill J., Winckler M. (eds) Human-Computer Interaction – INTERACT 2017. INTERACT 2017. Lecture Notes in Computer Science, vol 10514. Springer, Cham