PDFs and dark mode have an uneasy relationship. Most PDFs are designed with white backgrounds and dark text — the exact opposite of dark mode. When a dark mode user opens a PDF, they either see a blinding white document in an otherwise dark interface, or the viewer attempts to invert colors with results that range from acceptable to unusable. Making a PDF dark-mode friendly requires understanding what's actually possible.
The Fundamental Problem With PDFs and Dark Mode
PDF is a fixed-layout format — colors are embedded in the file, not controlled by the viewer's theme. A white background in a PDF is a literal white rectangle drawn on the page. Unlike HTML, where dark mode CSS can change background colors dynamically, a PDF's colors are baked in. The viewer can display dark mode around the PDF — the scrollbars, toolbars, and UI — but the PDF content itself stays white unless the viewer takes specific steps to override it.
This is why some PDF viewers show a white PDF in a dark UI, creating a jarring contrast. Others invert the PDF colors automatically — turning white to dark grey and black text to near-white. The inversion approach works reasonably well for text documents but breaks documents with photographs (photos look like negatives) and documents using color for meaning (charts, maps, diagrams).
Viewer Settings: The Easiest Fix for Readers
For people who want to read PDFs more comfortably in dark environments without modifying the file, viewer settings are the first option:
- Adobe Acrobat/Reader: Edit > Preferences > Accessibility, enable "Replace Document Colors," and set a custom color scheme — dark background with light text. This overrides the PDF's colors for display without modifying the file.
- Chrome: doesn't invert PDF colors in dark mode by default. Some Chromebook users can use the accessibility high contrast settings to invert.
- Apple Books (iPhone/iPad): has a Night Theme option that applies a sepia or dark background to PDFs for more comfortable reading in low light.
- GoodReader and PDF Expert (iOS): third-party PDF apps with dedicated night mode features that apply dark backgrounds without inverting image colors.
Creating a Dark-Background PDF From the Source
If you're creating a PDF specifically for dark mode display — a presentation, a technical document, or any content where you control the design — build it with a dark background from the start. In PowerPoint or Keynote, set the slide background to dark grey or black and use light-colored text. Export to PDF. The result is a PDF that looks correct in dark mode environments and doesn't require viewer color overrides.
The tradeoff: a dark-background PDF looks wrong when printed on paper (dark backgrounds consume large amounts of ink) and looks out of place in a light-mode environment. If the document needs to work well in both contexts, a light-background design is more universally compatible, and readers who prefer dark mode can use viewer settings to adapt it.
Converting an Existing PDF to Dark Background
Converting an existing white-background PDF to dark background is technically complex and rarely produces clean results. The white background isn't a single object that can be recolored — it's typically the absence of any content, with the page canvas itself appearing white. Replacing it requires either adding a dark rectangle behind all content on every page, or processing each page through image editing software.
A practical approach for text-heavy PDFs: convert the PDF to Word using WukongPDF at www.wukongpdf.com, change the page background color and text color in Word, then re-export to PDF. This works cleanly for simple text documents but requires significant reformatting for complex layouts.
The Practical Recommendation
For readers: use your PDF viewer's color override settings for a viewer-side dark mode experience without modifying files. For creators distributing to dark mode users: a light-background PDF with clear contrast is more universally compatible than a dark-background one, and the reader's viewer handles the adaptation. For presentations designed specifically for dark environments: design dark from the start rather than converting afterward. PDF's fixed-layout nature makes true adaptive dark mode — like a website that responds to OS theme — not currently achievable within the PDF Format specification.