Dark Mode: Why It's Harder to Implement Well Than It Looks

Dark mode gets requested as if it's a simple color inversion, and the requests that come back after a first attempt are usually about the same handful of problems: text that's unreadable, images with jarring white backgrounds, and colors that meant something specific in light mode losing that meaning entirely in dark.

What actually breaks in a naive dark mode implementation

• Pure black backgrounds with pure white text, which is harsher on the eyes than a well-chosen dark gray and light gray pairing — the opposite of the eye strain relief dark mode is supposed to provide.
• Images and logos designed for a white background suddenly floating in an awkward white box against a dark page.
• Color-coded meaning — a green success state or red error state — losing contrast or looking different enough in dark mode that the meaning isn't as immediately clear.
• Shadows and depth cues that worked on a light background becoming invisible or looking wrong once the background itself is dark.

What actually makes it work well

Building the color system with both themes in mind from the start — the same discipline behind a genuinely useful style guide — rather than designing entirely in light mode and inverting it afterward. Every color needs an intentional dark-mode equivalent, not an automatic algorithmic inversion.

Dark mode done well feels like a second, equally considered design. Dark mode done as an afterthought feels like a bug report waiting to happen.

This connects to the same underlying principle as accessibility work generally — contrast and readability have to be verified in both themes independently, not assumed to carry over automatically from one to the other.