Why contrast is everyone's problem, not an edge case
Contrast failures are usually framed as an accessibility topic — and they are one, reinforced since the European Accessibility Act came into force in June 2025. But the affected audience is far larger than the standards suggest: every recipient reading on a phone outdoors, on a low-quality display or with tired eyes experiences low-contrast text the same way.
There is also a perception risk. Barely visible disclaimers or conditions read as an attempt to hide information, which damages trust in the brand itself.
Low contrast is not an edge case. It is every reader, in bright light.
WCAG contrast thresholds for email
How to read a contrast check
Two useful subtleties. Results should be volume-weighted: a failing paragraph matters more than a failing word. And text placed over background images cannot be measured reliably — it should be flagged separately, never guessed.
5 best practices
- Aim for 4.5:1 on all body text — including links and button labels: a button needs to be readable too.
- Watch light brand colors (yellows, oranges, bright blues) on white, the most common failures. Use them for backgrounds or large headlines, not body text.
- Never rely on a background image for readability: many clients block images, and your text then lands on the fallback color. Check the contrast against that color.
- Treat light grey on white (footers, legal mentions) as the classic trap — stay above 4.5:1, even for secondary text.
- Fix contrast upstream, in your email style guide, rather than campaign by campaign.
Common mistakes
- Validating contrast in the design file only: dark mode in some email clients alters colors after sending.
- Using color alone to carry meaning — a red price, a green “in stock” — without a text cue.
- Testing text over a gradient or a photo at its darkest point instead of its lightest.
- Correcting one campaign while the template it came from keeps the failing colors.
How Inbox Maestro checks it
Inbox Maestro extracts each text/background combination from your test email, measures its exact ratio and classifies it against WCAG AA, weighted by the volume of text concerned. For every failing pair, it calculates a compliant corrective color. The result appears in the Checkup section of your report, under Composition.
Frequently asked questions
What contrast ratio does an email need?
WCAG AA requires 4.5:1 for normal text and 3:1 for large text (24 px and above, or about 18.5 px bold). These thresholds apply to every text/background combination, button labels included.
Is email contrast covered by the European Accessibility Act?
The EAA, in force since June 2025, relies on accessibility standards derived from WCAG for the services it covers, such as e-commerce. Whether a given campaign falls in scope depends on the service it relates to — but contrast is one of the most directly measurable criteria, and one of the easiest to fix.
Is there a US equivalent to the European Accessibility Act?
Not for private businesses. The ADA has no regulation setting a technical standard for commercial digital content, but courts commonly rely on WCAG 2.1 Level AA in accessibility cases — the same standard the Department of Justice adopted in 2024 for state and local government websites. For email teams, the practical reference is the same on both sides of the Atlantic: WCAG AA contrast thresholds of 4.5:1 for normal text and 3:1 for large text.
Can I measure contrast over a background image?
Not reliably — the background varies pixel by pixel. Measure against the fallback background color instead, since that is what recipients see when images are blocked.
What are the most common contrast failures in email?
Light grey on white (footers, legal text), light brand colors used for body copy on white, and white text on insufficiently dark brand colors — buttons included.