Improving our design system through Dark Mode
Etsy recently launched Dark Mode in our iOS and Android buyer apps. Since Dark Mode was introduced system-wide last year in iOS 13 and Android 10, it has quickly become a highly requested feature by our users and an industry standard. Benefits of Dark Mode include reduced eye strain, accessibility improvements, and increased battery life. For the Design Systems team at Etsy, it was the perfect opportunity to test the limits of the new design system in our apps.
In 2019, we brought Etsy’s design system, Collage, to our iOS and Android apps. Around the same time, Apple announced Dark Mode in iOS 13. By implementing Dark Mode, the Design Systems team could not only give users the flexibility to customize the appearance of the Etsy app to match their preferences, but also test the new UI components app-wide and increase adoption of Collage in the process.
Without semantic colors, Dark Mode wouldn’t have been possible. Semantic colors are colors that are named relative to their purpose in the UI (e.g. primary button color) instead of how they look (e.g. light orange color). Collage used a semantic naming convention for colors from the beginning. This made it relatively easy to support dynamic colors, which are named colors that can have different values when switching between light and dark modes. For example, a dynamic primary text color might be black in light mode and white in Dark Mode.
Dynamic semantic colors opened up the possibility for Dark Mode, but they also led to a more accessible app for everyone. On iOS, we also added support for the Increased Contrast accessibility feature which increases the contrast between text and backgrounds to improve legibility. Any color in the Etsy app can now have up to four values for light/dark modes and regular/increased contrast.
To streamline the process for adding new colors, we created a script on iOS that generates all of our color assets and files. With the growing complexity of dynamic colors, having a single source of truth for color definitions is important. On iOS, our source of truth is a property list (a key-value store for app data) of color names and values. We created a script that automatically runs when the app is built and generates all the files we need to represent colors: an asset catalog, convenience variables for accessing colors in code, and a source file for the unit tests. Adding a new color is as simple as adding a line to the property list, and all the relevant files are updated for you. This approach has reduced the time it takes to add a new color and eliminated the risk of inconsistencies across the codebase.
Another design change we made for Dark Mode was rethinking how we represent elevation in our UI components. In light mode, it’s common to add a shadow around your view or dim the background to show that one view is layered above another. In Dark Mode, these approaches aren’t as effective and the platform convention is to slightly lighten the background of your view instead. The Etsy app uses shadows and borders extensively to indicate levels of elevation. For Dark Mode, we removed shadows entirely and used borders much more sparingly. Instead, we followed iOS and Android platform conventions and introduced elevated background colors into our design system. Semantic colors came to the rescue again and we were easily able to use our regular background color in light mode while applying a lighter color in Dark Mode on views that needed it, such as listing cards.
Choose your theme
There is no system-level Dark Mode setting available on older versions of Android, but it can be enabled for specific apps that support Themes (an Android feature that allows for UI customization and provides the underlying structure for Dark Mode). This limitation turned into an opportunity for us to provide more customization options for all our users. In both our iOS and Android apps you can personalize the appearance of the Etsy app to your preferences. So if you want to keep your phone in light mode but the Etsy app needs to be easy on the eyes for late night shopping, we’ve got you covered.
Dark Mode in web views
Another obstacle to overcome was our use of web views, a webpage that is displayed within a native app. Web views are used in a handful of places in our iOS and Android apps, and we knew that for a great user experience they needed to work seamlessly in Dark Mode as well. Thankfully, the web engineers on the Design Systems team jumped in to help and devised a solution to this problem. Using the Sass
!default syntax for variables, we were able to define default color values for light mode. Then we added Dark Mode variable overrides where we defined our Dark Mode colors. If the webpage is being viewed from within the iOS or Android app with Dark Mode enabled, we load the Dark Mode variables first so the default (light mode) color variables aren’t used because they’ve already been defined for Dark Mode. This approach is easy to maintain and performant, avoiding a long list of style overrides for Dark Mode.
A better design system
Implementing Dark Mode was no small task. It took months of design and engineering effort from the Design Systems team, in collaboration with apps teams across the company. A big thank you to Patrick Montalto, Kate Kelly, Stephanie Sharp, Dennis Kramer, Gabe Kelley, Sam Sherman, Matthew Spencer, Netty Devonshire, Han Cho and Janice Chang. In the end, our users not only got the Dark Mode they’d been asking for, but we also developed a more robust and accessible design system in the process.