CSS Properties

accent-color

CSS property · 5 supported, 0 partial, 15 unsupported across 21 clients

As of Sep 2, 2026, accent-color fails or degrades in 16 of 21 email clients, treat it as progressive enhancement, never structure.

1/7 webmail, 2/6 desktop, 2/8 mobile clients support accent-color fully.
Unsupported in Gmail, Gmail Android, Gmail iOS, Outlook 365 and 11 more.
Outlook Classic (Word engine, supported to at least 2029) does not fully support accent-color, and its replacement changes little here; see the deprecation diff.
Across all clients, only 6 of 298 tracked HTML/CSS features render identically everywhere.

Source: caniemail.com (MIT), via the Emailens engine. Last tested upstream Dec 19, 2023, synced by Emailens Sep 2, 2026.

accent-color applies a custom tint to native form controls (checkboxes, radio buttons, range sliders). Email forms are largely stripped or ignored by clients for security reasons, so accent-color is mostly a no-op in production email , but it is harmless to include for the few clients that render forms.

Client Support

Client	Category	Engine	Support
Gmail	webmail	Gmail Web	Unsupported
Gmail Android	mobile	Gmail Mobile	Unsupported
Gmail iOS	mobile	Gmail Mobile	Unsupported
Outlook 365	webmail	Outlook Web	Unsupported
Outlook (New)	desktop	Outlook Web	Unsupported
Outlook Classic	desktop	Microsoft Word	Unsupported
Outlook iOS	mobile	Outlook Mobile	Unsupported
Outlook Android	mobile	Outlook Mobile	Unsupported
Outlook for Mac	desktop	WebKit	Unsupported
Apple Mail	desktop	WebKit	Supported
Apple Mail iOS	mobile	WebKit	Supported^{See caveat 1}
Yahoo Mail	webmail	Yahoo	Unsupported
Yahoo Mail Android	mobile	Yahoo	Unsupported
Yahoo Mail iOS	mobile	Yahoo	Unsupported
Samsung Mail	mobile	Samsung	Supported^{See caveat 1}
Thunderbird	desktop	Gecko	Unknown
HEY Mail	webmail	WebKit	Supported
Proton Mail	webmail	Proton	Unsupported
AOL Mail	webmail	AOL	Unsupported
Fastmail	webmail	Fastmail	Unsupported
Superhuman	desktop	Blink	Supported

Documented caveats (1)

1.Apple Mail iOS, Samsung Mail: Supports accent-color but rendering depends on browser support.

Caveats recorded by caniemail.com (MIT) and carried verbatim, one entry per wording rather than per client.

Client-by-client behaviour for accent-color

Fully supports accent-color (5): Apple Mail, Apple Mail iOS, Samsung Mail, HEY Mail, Superhuman.

No support (15): Gmail, Gmail Android, Gmail iOS, Outlook 365, Outlook (New), Outlook Classic, Outlook iOS, Outlook Android, Outlook for Mac, Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, Proton Mail, AOL Mail, Fastmail. Plan fallbacks for these clients before relying on accent-color in production sends.

Behaviour unverified in: Thunderbird.

When to use accent-color in email

Brand-tinted checkboxes in interactive AMP for Email contexts.
Custom-colored radio inputs in clients that support form rendering (rare).
Range slider styling in experimental email-as-app interfaces.

Rendering behaviour and edge cases

Most major clients strip <input> elements entirely, making accent-color irrelevant.
Gmail's AMP for Email path supports limited form interaction but does not honor accent-color.
accent-color is safe to include as a future-proofing declaration without breaking layout in clients that ignore it.

Recommended fallback strategy

Do not rely on form-element styling in email. If interactivity is needed, design around button-style anchor tags that link out to a hosted experience, and reserve accent-color for clients that explicitly render forms.