What is Dark Mode in Emails
Dark Mode is a user or device preference where UI elements or content are displayed with dark backgrounds and light text (or otherwise inverted colors) to reduce bright glare, reduce eye strain, and often save battery on OLED screens. Many email clients, mobile OSes, and apps now support dark themes. When enabled, they can automatically invert or adjust the color scheme of emails unless the email is designed to handle it properly.
Why Dark Mode Matters, Especially for Mobile-First Campaigns
- High Mobile Usage + Preference
- Most users check emails on mobile, often in low-light environments (evenings, bedrooms, etc.). Dark mode is easier on the eyes in such conditions.
- Many device users prefer dark themes system-wide. Android, iOS, many modern email apps support toggling dark mode. (ZipDo)
- User Experience & Accessibility
- Improves readability under certain conditions. Reduces glare on bright white backgrounds. Helps reduce eye strain.
- Helps users with visual sensitivities. Strong contrast and well-chosen colors matter. (Microsoft Learn)
- Brand Perception and Trust
- If an email is badly rendered (logo invisible, text unreadable, layout broken), it undermines brand professionalism.
- A design that “breaks” under dark mode can look like a bug or weak QA.
- Trend & Competitive Expectation
- Increasing percentage of email opens happen in dark mode or on devices with dark theme. Marketers are catching on. (salesso.com)
- As more brands optimize for dark mode, consumers may begin to expect it.
How Email Clients Deal with Dark Mode (and Why It Varies)
Different clients (Gmail, Apple Mail, Outlook, etc.) handle dark mode in different ways:
- Automatic color inversion / background/text color swapping
Some clients auto-invert white backgrounds/dark text to dark backgrounds/light text (or do some variant). But this is often uncontrolled from the sender’s side. (Experience League) - Support for custom CSS / media queries
Some clients (especially more modern ones) support@media (prefers-color-scheme: dark)to provide custom styling for dark mode. This gives more control. (Klaviyo Help Center) - Clients with no support / partial/unnamed behavior
Some email apps either don’t support dark mode at all, or have partial or undocumented behavior. This means testing is essential. (Experience League) - Variability across devices
Even the same email viewed on iPhone vs Android vs desktop vs webmail may render differently under dark mode. Differences in how backgrounds, images, logos are handled, especially with transparency, inversion, etc. (rejoiner.com)
Key Statistics / Trends
Here are data points showing how big dark mode is now, and how marketers are responding:
| Stat | Source / Detail |
|---|---|
| ~34% of email opens were in dark mode (Aug 2022) | Litmus report, showing sizeable share of opens in dark mode. (Mailmodo) |
| Only ~5% of emails were optimized for dark mode by mid-2022 | Shows the gap between user behavior / preference vs what marketers are doing. (Mailmodo) |
| Many marketers plan to incorporate dark mode into email production: ~44%; additional ~28% planning to start | From Mailjet/Litmus surveys. (Mailmodo) |
| Use of dark mode by mobile users is very high (Android / system-wide) | Multiple sources report strong adoption among mobile devices. (Selzy) |
Design & Coding Best Practices
To make your emails look good in both light and dark modes, particularly for mobile, here are practical guidelines:
- Avoid pure black / pure white extremes
- Instead of #000000 or #FFFFFF, use very dark gray (e.g. #121212 or #1A1A1A) and off-white for backgrounds and text. This reduces harsh contrast and helps avoid unwanted inversion artifacts. (Microsoft Learn)
- Use transparent (PNG) backgrounds / images wisely
- Transparent PNGs for logos/icons help avoid white boxes or awkward backgrounds.
- If transparent doesn’t work (due to visibility issues), consider adding subtle strokes or glows around logos/icons to help when in dark mode. (help.drip.com)
- Limit embedded text in images
- Text that’s part of images doesn’t adapt (invert or reflow) well under dark modes; can become unreadable. Better to use live HTML text wherever possible. (Klaviyo Help Center)
- Ensure sufficient contrast for text, buttons, CTAs
- Contrast needs to be high in both light vs dark modes. Avoid color combinations that blend when inverted or under dark backgrounds.
- Borders or outlines on buttons and icons help preserve visibility. (help.drip.com)
- Design for both modes / use conditional styles
- Use CSS
@media (prefers-color-scheme: dark)when possible to deliver custom styles for dark mode. (Klaviyo Help Center) - But note: not all clients support this. So always have fallbacks / check how your design degrades. (Experience League)
- Use CSS
- Watch images carefully
- Images with solid light backgrounds may be inverted oddly or look bad.
- Add padding around non-transparent images, so they don’t visually “bleed” into background when inversion or surrounding background changes occur. (support.yotpo.com)
- Button design
- Buttons should be clearly visible; use stroke or outline, avoid invisible borders.
- Test CTA visibility in dark backgrounds. Beacon or glow or contrasting border helps. (help.drip.com)
- Fonts & typography
- Use fonts thick enough for readability. Thin fonts may disappear or look faint in dark mode.
- Use sizes large enough to read on mobile. Clear headings, spacing, line height matter more when contrast is lower. (Microsoft Learn)
- Fallbacks and testing
- Always test your emails on multiple email clients and on mobile devices, in both light & dark mode. Tools like Litmus, Email on Acid, etc. (rejoiner.com)
- Preview how images and icons render, check layout, check if any elements disappear or become unreadable.
- Keep design simple / avoid overly complex backgrounds
- Gradient backgrounds, overly busy patterns may look great in light mode but collapse poorly in dark mode.
- Simplify: fewer colors, cleaner layouts tend to hold up better. (support.yotpo.com)
Challenges & Risks
Designing for dark mode isn’t trivial. Here are the main challenges you’ll face:
- Email client inconsistencies: Because each client may render differently, you can’t guarantee uniformity. What looks good in Apple Mail may misbehave in Gmail mobile or Outlook.
- Automatic inversion may break design: Logos, images, color blocks may invert in ways that harm readability or brand preservation.
- Additional design / development time: Creating alternate assets, outlining logos, adding fallbacks takes extra work.
- Image loading / performance trade-offs: If you use big images to preserve backgrounds or color fidelity, you may hurt load times / deliverability.
- Risk of broken readability: If contrast is too low, or text is too thin/buttons not visible, content may become unreadable, which may frustrate users, or worse, make the email look broken.
Implementation Steps & Checklist for Mobile-First Campaigns
Here’s a step-by-step plan / checklist if you want to adopt dark mode design in your email program, especially for mobile-first campaigns:
| Step | What to Do |
|---|---|
| 1. Audit current templates & campaigns | Review your existing email templates: logos, icons, images, background colors. Send some sample emails in dark mode devices to see how they render. |
| 2. Identify audience & client mix | Find out which email clients your audience uses (via your analytics). See how many opens are from mobile, how many from clients supporting dark mode, etc. Helps prioritize effort. |
| 3. Define brand color palette with dual mode in mind | Choose dark and light compatible colors; decide what background and text colors to use in both modes; define logo versions / icon versions. |
| 4. Design assets accordingly | Create or adjust images / logos: transparent backgrounds, or versions for dark mode; include halos or strokes for visibility. |
| 5. Code templates with conditional styling | Use HTML/CSS where possible; include @media (prefers-color-scheme: dark) conditions if supported; include fallback colors. |
| 6. Optimize for mobile first | Ensure font sizes, touch-friendly buttons, responsive layouts. On mobile, spacing, legibility become more critical. |
| 7. Test broadly | Use tools like Litmus / Email on Acid / other ESP previews; test on actual devices (iOS, Android) in both modes; test clients your audience uses heavily. |
| 8. Monitor performance & feedback | After rolling out, watch for metrics: opens, CTR, unsubscribe / spam complaints, heatmaps if possible; also gather qualitative feedback (does content look bad, weird background flashes, etc.). |
| 9. Refine iteratively | Based on test and performance, adjust colors, images, layout elements. You may need “dark mode-only” asset versions for certain elements. |
Example / Mini Case Scenarios
Here are some hypothetical / aggregated examples showing what design changes may look like:
- Scenario A: Logo disappears
A brand uses a dark‐colored logo with transparent background. In dark mode, the background is dark so the logo blends in (or disappears). Fix: add a light border or outline around logo; alternatively have a version of the logo with a light background OR invert logo when in dark mode via conditional asset. - Scenario B: Button CTA is invisible
Button with white text on a transparent background or light pastel colour works in light mode; in dark mode maybe the text or background get inverted or lose contrast. Fix: ensure CTA has border, background fill, or colors that preserve contrast; test in dark mode. - Scenario C: Text embedded in image becomes unreadable
If you have headings or banners that are images (with text), embedded text can be inverted (color shift) or background colors may clash, making text unreadable. Fix: where possible use live text; if image needed, ensure good contrast or have alternate version for dark mode.
Business Benefits of Doing It Well
- Better experience → higher engagement: Users are more likely to read, interact, click when emails are easy on the eyes.
- Lower risk of unsubscribes / complaints: If email renders poorly, people may mark as spam or unsubscribe.
- Improved brand trust & professionalism: Shows attention to detail; consistency across contexts (light/dark, mobile/desktop) strengthens brand.
- Future-proofing: As more OSes, app clients push dark mode or include system preferences, being ready means you’re not scrambling later.
- Possibly better deliverability / algorithmic benefit? There’s less published data here, but emails that look “broken” or low quality may have higher bounce or spam rates.
when It Might Be Less Critical / Exceptions
- If your audience is known to mostly use email clients that don’t support dark mode, or mostly cheerful bright displays, the ROI on full dark mode optimization may be lower.
- If resources are limited (designer/dev bandwidth), you might focus first on critical templates (welcome flows, high-volume campaigns) before extending to all campaigns.
- If your email content is very simple (mostly text, minimal styling), the risk of breaking is lower, so investment might be moderate.
- I searched for documented case studies specifically showing performance data of dark mode-optimized emails (especially in B2B), but didn’t find many with real KPIs. Most sources are more about experiments, best practices, user feedback, or design explorations. Below are the closest things I found, plus what they teach us. If you want, I can try to dig into paid reports to find ones with conversion uplift numbers.
What I Found: Near-Case Studies & Experiments
Source What they did / observed What was learned (relevant to case-study style) Adobe Journey Optimizer – “Dark mode for email content” This is a tool-provider documentation of how to support dark mode. It includes how designers can preview dark mode, define custom dark mode styles, and have alternative image assets. (Experience League) Not a campaign result, but shows many brands are using this type of tool. It confirms that businesses are investing in having dual-mode views. It also underscores that different email clients behave differently, so “case” experiences vary. Moosend blog – Build Dark Mode Friendly Email Campaigns They examined how email clients invert or partially invert colors, showed examples, and explained how dark mode can break or degrade non-optimized emails. (The Easiest Email Marketing Platform) Their experiments show that unoptimized emails can look very bad: e.g. unreadable text, mis-colored CTAs. So even if a campaign doesn’t publish uplift numbers, the negative costs (in terms of branding, engagement loss) can be real. Kenscio – Designing Emails for Nighttime Readers with Dark Mode This is more of a thought piece with some data: e.g. “emails optimized for dark mode have a 15% higher read rate than non-optimized ones (Litmus)” cited. (Kenscio) So there is some quantitative signal: read/open rates appear to improve when email is dark mode friendly. But we don’t know the full funnel (clicks, conversions). Mailmodo statistics & surveys They report stats like ~34% of email opens are in dark mode (as of mid-2022), that dark mode optimization is still rare (~5%), but increasing. (Mailmodo) These stats serve as leading indicators that dark mode is materially relevant, which in itself drives organizations to test and optimize. But again, not full case studies with revenue or conversion uplift.
What We Don’t (Yet) See Enough Of
- Clear before-vs-after A/B tests of a campaign that had a “light-only” version vs a dark-mode optimized version, showing lift in clicks, conversions, or revenue.
- Full campaign metrics tied to dark mode redesigns in B2B (e.g. effect on MQLs / SQLs).
- Longitudinal tracking: do dark mode improvements hold up, or do users get fatigued / does novelty wear off.
What Case-Study-Like Insights We Can Extract Anyway
Even without full campaign performance numbers, there are design experiments / observations that behave like mini-case studies. Here are what they reveal in practice:
- Readability & Engagement Gains
When emails are optimized for dark mode (good contrast, correct logo visibility, visible CTA buttons), open/read rates tend to improve. Kenscio’s cited “15% higher read rate” is an example. (Kenscio) - Brand Perception / User Trust Improved
Users notice when emails are messy under dark mode: logos “invisible,” text blending into background, etc. Those degrade trust/brand perception. When design handles dark mode well, the negative effects are mitigated. Moosend and Dartagnan reports note that very messy dark mode rendering causes frustration or even unsubscriptions. (The Easiest Email Marketing Platform) - Design Overhead is Non-Trivial but Payoff is Risk Mitigation
The investment in alternative assets, testing across clients, fallback styling etc., is real. But failing to do so can lead to significant design “breakage” (e.g. invisible text or CTAs), which likely reduces click-throughs. So even without “100% perfect dark mode,” ensuring the email is usable under dark mode is a protective measure. (cmercury.com) - Design Adaptations / Best Practices Pay Off
Some specific tweaks appear beneficial, e.g.:- Using transparent PNGs for logos/icons so they don’t have white boxes or vanish in dark backgrounds. (Experience League)
- Adding light-colored outlines or shadows to dark logos for visibility. (Kenscio)
- Avoiding pure black (#000) / pure white (#fff) backgrounds or text, prefer dark grays / off-whites to reduce harsh contrasts and reduce risk of inversion issues. (Experience League)
- Testing across email clients and on devices in real dark mode. Litmus and other tools are often cited. (Experience League)
Suggested Mini Case Study Framework (Hypothetical / How One Might Do It)
Since full published ones are sparse, here’s how you could conduct or evaluate a case study of your own (or look for it in others’ reports):
Step What-to-Measure Why It Matters Baseline Pick a recent campaign email that was designed without dark-mode considerations; gather metrics: opens, CTR, conversion rate, device/client breakdown. Needed to compare. Design dark-mode-friendly version Adjust assets, contrast, logos, colors; possibly include custom CSS for prefers-color-scheme: dark.To ensure dark mode readability & aesthetics. Split test / A/B send Send to random halves of audience, or segment by email client types (devices known to support dark mode vs others). To isolate impact. Measure lifts Compare opens / reads, CTRs, conversion (e.g. demo signups, downloads), maybe also observe unsubscribe/spam complaints. To quantify benefit. Qualitative feedback Survey or note user feedback, aesthetic complaints, how email looked under dark mode. Branding & perception often is “hidden” but important. Iterate Based on data, adjust design investments, prioritize templates that deliver biggest improvements. Makes your efforts efficient.