How should I handle Samsung Internet’s automatic dark-mode color changes?

Older websites sometimes detected specific browsers and displayed a recommendation to install something else, but that’s generally not worth doing today. Users can have tinted displays, different brightness levels, saturation settings, or accessibility filters too. Aim for a robust, accessible design rather than trying to control every possible rendering environment.

You ultimately don’t control the client. You can detect the browser and show a warning, but asking people to switch browsers is usually a poor user experience. Build a solid default design, then accept that device settings and browser behavior may alter the final result.

Set the color-scheme hint in the document head and give important elements explicit background and foreground colors instead of relying on inherited or browser-default values. Forced dark-mode transformations are more likely to preserve those declared color pairs. Also avoid putting text over complex images or gradients, and make your color combinations high-contrast in the first place.

This kind of forced-color feature may not be detectable. The browser can present itself as using a light theme while making its own color changes afterward, so JavaScript and media queries may not reliably tell you what happened. There may simply be no webpage-level switch that disables it.