Why Transparent PNG Images Look Wrong in Dark Mode on E-Readers

Transparent PNG images look wrong in ebook dark mode because e-readers fill the transparent areas with their background color — black or near-black — causing dark artwork and text to vanish or white boxes to appear around images. Amazon Kindle strips transparency entirely and substitutes a white background, while Apple Books renders transparent areas as pure black in night mode. The fix is straightforward: use images with solid, opaque backgrounds instead of relying on transparency.

How Alpha Channels Work in PNG Images

A PNG image can store four channels of data per pixel: red, green, blue, and alpha. The alpha channel holds transparency information as an 8-bit value ranging from 0 (fully transparent) to 255 (fully opaque), giving each pixel one of 256 possible transparency levels. This is what allows PNG images to have smooth, anti-aliased edges and partially see-through areas — unlike GIF, which only supports binary transparency where a pixel is either fully visible or fully invisible.

When you save a decorative chapter header, section divider, or title page ornament as a PNG with a transparent background, the alpha channel tells the rendering software to show whatever is behind the image. In a web browser or design application, that background is usually white or a colour you control. In an ebook reader, the background is whatever the reader’s current theme dictates — and that is where things break.

In light mode, the e-reader’s background is white or cream, so transparent areas appear as expected. Switch to dark mode, and those same transparent areas are now filled with black or dark grey. Any dark-coloured artwork, text, or fine detail in your image that was designed to be seen against a light background becomes invisible — dark on dark.

How Amazon Kindle Handles Transparent PNGs

Amazon Kindle does not support PNG transparency at all. When you upload an EPUB or KPF file containing transparent PNG images, KDP’s processing pipeline automatically converts every transparent area to a solid white background. This is documented in Amazon’s Kindle Publishing Guidelines.

The result is predictable: your image looks fine in Kindle’s default light reading mode, because the white background blends with the white page. But the moment a reader switches to one of Kindle’s darker themes — Sepia, Green, or the fully dark theme — a stark white rectangle appears around every image that originally had transparency. For decorative elements like chapter headers, ornamental dividers, or stylised drop caps, this white box is visually jarring and immediately signals that something has gone wrong with the formatting.

This is a platform-level constraint, not a bug in your formatting tool. If you use Vellum, Atticus, Sigil, or any other EPUB editor, the transparent areas will still be converted to white by KDP regardless of how the file was built.

Why Dark Artwork Disappears in Apple Books Night Mode

Apple Books takes the opposite approach to Kindle: it preserves PNG transparency. In the default light theme, this works as intended — transparent areas show the white page background, and your images look exactly as designed. The problem appears in night mode.

When a reader activates night mode in Apple Books, the page background becomes black. Because the alpha channel is preserved, transparent areas in your images are now rendered against that black background. Any dark-coloured text, line art, or decorative elements in the image become invisible — black artwork on a black background. The Apple Books Asset Guide (version 5.3.1, updated February 2025) explicitly recommends using JPEG with a white background instead of transparent PNG for images containing dark text.

This failure mode is especially common with title page images. Authors often create elegant title pages with dark calligraphic text on a transparent background, expecting the e-reader to supply a white backdrop. In light mode it looks perfect. In Apple Books night mode, the text vanishes entirely. If your images are already breaking during Word-to-EPUB conversion, adding transparency issues on top compounds the problem.

How Kobo and Google Play Books Handle Transparency

Kobo’s dark mode works by inverting the display rather than simply changing the background colour. This means image transparency handling varies by device model and firmware version. Some Kobo devices invert the entire image (which can make photos look like negatives), while others leave images untouched and only invert the surrounding text and page colour. The result is inconsistent: a transparent PNG might look acceptable on one Kobo device and broken on another.

Google Play Books has limited EPUB3 support and handles transparency inconsistently across its Android app, iOS app, and web reader. Transparent areas may render as white, black, or the platform’s current background colour depending on the reading context. There is no reliable way to predict or control this behaviour across all Google Play reading surfaces.

The fragmented behaviour across platforms is the core problem. An image that looks fine on one device or app may be completely broken on another, and you have no way to test every combination of platform, device, and reading mode your readers will use.

What Vellum and Other Formatting Tools Do with Transparent Images

Vellum, the popular Mac-based ebook formatting tool, adds white backgrounds to transparent PNG images when generating Kindle-format files. This is intentional — Vellum is pre-emptively doing what KDP would do anyway during upload processing. For EPUB files destined for Apple Books or other platforms, Vellum preserves the original transparency, which means the dark-mode visibility problem remains on those platforms.

Other formatting tools behave differently. Atticus preserves transparency across all output formats. Sigil and Calibre pass through whatever image data you provide without modification. Amazon’s own Kindle Create tool converts transparency to white, matching KDP’s pipeline behaviour. The key point is that no formatting tool can solve the underlying problem — the e-reader’s dark mode rendering is outside the tool’s control.

If you are working with interior book images, understanding the right DPI and format for your images is equally important, since resolution and format choices affect how your images render across all reading modes.

How to Prepare Ebook Images That Work in Every Reading Mode

The most reliable fix is to avoid transparency altogether. Save your ebook images as JPEG or as PNG with a solid opaque background. For most decorative elements — chapter headers, section dividers, title page images, ornamental flourishes — a white background works in light mode and produces a predictable (if imperfect) white box in dark mode, which is less disruptive than invisible artwork.

If you want your images to look good in both light and dark modes, consider these approaches:

• Use a neutral mid-tone background. A light grey (such as #F0F0F0) blends reasonably well in light mode and creates a softer contrast in dark mode than pure white.
• Create two versions of each image — one for light backgrounds and one for dark — and use CSS @media (prefers-color-scheme: dark) to swap them. This works in Apple Books and some Kobo devices, but Kindle does not support this CSS query, so the light-mode version will always display there.
• Add a thin border or subtle drop shadow to images with white backgrounds. This visually separates the image from the page in both light and dark modes and looks intentional rather than broken.
• For text-based decorative elements, consider using styled HTML text instead of images. HTML text automatically adapts to the reader’s colour scheme in dark mode, eliminating the problem entirely.

Understanding the difference between reflowable and fixed-layout EPUB formats also matters here, since fixed-layout EPUBs give you more control over image placement but are not supported by all e-readers.

Frequently Asked Questions

Can I use CSS to fix transparent PNG images in ebook dark mode?

The CSS media query @media (prefers-color-scheme: dark) can swap images or apply filters for dark mode in Apple Books and some Kobo devices, but Amazon Kindle does not support this query. Since Kindle represents the largest share of ebook readers, CSS alone cannot provide a universal fix. The most reliable approach is using images with solid opaque backgrounds.

Does Kindle support any form of image transparency?

No. Amazon Kindle does not support PNG alpha channel transparency. KDP’s upload process automatically converts all transparent areas to white backgrounds. This applies regardless of which formatting tool you use to create the ebook file — the conversion happens on Amazon’s end during processing.

Should I use JPEG or PNG for ebook interior images?

For photographic images and any image that does not require transparency, JPEG is the better choice for ebooks. It produces smaller file sizes and avoids the dark mode transparency problem entirely. Use PNG only when you need sharp edges on line art or diagrams, and always save with a solid background colour rather than transparency.

Why does Vellum add a white background to my transparent images?

Vellum adds white backgrounds to transparent PNG images specifically when generating Kindle-format files, because Kindle does not support transparency and would add the white background anyway during KDP processing. This is a deliberate compatibility measure, not a bug. For EPUB files targeting Apple Books and other platforms, Vellum preserves the original transparency.

What ebook elements are most affected by dark mode transparency issues?

The most commonly affected elements are decorative chapter headers, section dividers, ornamental flourishes, stylised drop caps, and title page images — particularly any image containing dark text or fine line art on a transparent background. These elements were typically designed for light backgrounds and become invisible or display white boxes when viewed in dark mode.