<meta name="theme-color">
Tints the browser chrome and OS surfaces to match your brand. Use the media attribute to ship one colour for light mode and another for dark mode.
What it is
theme-color suggests a colour for the browser or OS to use when rendering surfaces around the page — the address bar on mobile, the title bar of an installed PWA, the task switcher card, and notification accents.
<meta name="theme-color" content="#0b1020" />The value is any valid CSS colour: hex, rgb(), hsl(), or a named colour.
Why it matters
Mobile browsers render a thin strip above the page — the URL bar in Safari and Chrome on iOS and Android. By default it is grey or white. With theme-color, that strip can match your brand, so the page and the chrome around it look like one continuous surface.
The same value is used by:
- iOS Safari to tint the status bar area when scrolled.
- Chrome on Android for the address bar and the task switcher card.
- PWAs and installed web apps for the system title bar.
- macOS Safari 15+ to tint the tab bar of the focused tab.
A page without theme-color is not broken, but the visual seam between page content and browser chrome is more obvious. With it, the page feels polished and “native-ish” on mobile.
How to implement
Set one value for light mode and one for dark mode using the media attribute:
<meta name="theme-color" content="#ffffff" media="(prefers-color-scheme: light)" />
<meta name="theme-color" content="#0b1020" media="(prefers-color-scheme: dark)" />Browsers pick the value whose media query matches the user’s current colour scheme. If only one tag is present, it is used in every mode — fine for sites with a single fixed palette.
Pick colours that match the edges of your page, not the centre. The strip sits flush against your <body> background; if your header is dark and the rest of the page is light, the theme colour should match the header.
For an installed PWA, the manifest’s theme_color and background_color are used at launch. Set both for a smooth splash:
{
"name": "The Website Specification",
"theme_color": "#0b1020",
"background_color": "#0b1020"
}The manifest value is used once at install/launch time; the meta tag is consulted on every page load. They can differ if you want a different colour during the splash than during normal browsing, but matching them avoids a visible jump.
When you ship a manual theme toggle
The media-based tags follow the operating system, not an in-page switcher. If you let users force dark mode independently of the OS, a visitor on a light OS who picks dark gets a dark page with a light address bar — the (prefers-color-scheme: light) tag still matches. The chrome and the content disagree.
Fix it in script: write a single theme-color value that reflects the resolved theme, and make sure it wins. Browsers read the first theme-color meta in document order whose media matches, so insert your dynamic tag ahead of the media ones:
function syncThemeColor(theme) {
let m = document.querySelector('meta[name="theme-color"]:not([media])');
if (!m) {
m = document.createElement('meta');
m.name = 'theme-color';
document.head.prepend(m); // ahead of the media-based tags, so it wins
}
m.content = theme === 'dark' ? '#0b1020' : '#ffffff';
}Set it before paint in the same inline script that restores the stored theme, then keep it in sync whenever the user toggles. Leave the two media tags in place as the no-JS fallback. This site does exactly that — see the early-init script in BaseLayout.astro and theme-toggle.js.
Common mistakes
- A theme colour with low contrast against the address-bar text. Safari and Chrome render the URL in dark or light text based on the luminance of
theme-color; an unreadable URL is a real bug. - Setting only the dark-mode value, so light-mode users see the default grey.
- Relying on the
media-based tags alone while shipping an in-page dark-mode toggle. They track the OS, so a manual override leaves the chrome out of step — drivetheme-colorfrom the resolved theme instead. - Forgetting to update the value when redesigning. The address bar starts looking off-brand months before anyone notices.
- Animating it on scroll. It is metadata, not a paint surface — leave it static.
- Putting hex values with alpha (
#0b1020aa). Browsers ignore the alpha channel; use an opaque colour.
Verification
- Open the site on iOS Safari or Chrome on Android. The address bar should be tinted to match your site.
- Toggle the OS between light and dark mode. The strip should change.
- Install the site as a PWA and check the title bar and splash screen colours.
- In DevTools, run
document.querySelector('meta[name="theme-color"]').contentand confirm the value.