--- title: "No theme-color meta (seo/theme-color)" description: "seo/theme-color: Mobile browsers tint UI with theme-color; light and dark variants avoid a mismatched bar." canonical: https://void-design.vercel.app/rules/seo/theme-color lastModified: 2026-09-16 --- # No theme-color meta `seo/theme-color` · severity **info** · category SEO · detected by `void seo` and `void audit` ## Why it matters Mobile browsers tint UI with theme-color; light and dark variants avoid a mismatched bar. ## How to fix it Set viewport.themeColor (not metadata) with prefers-color-scheme variants. ## Example ```ts export const viewport: Viewport = { themeColor: [ { media: '(prefers-color-scheme: light)', color: '#ffffff' }, { media: '(prefers-color-scheme: dark)', color: '#0a0a0a' }, ], } ``` ## References - https://nextjs.org/docs/app/api-reference/functions/generate-viewport ## More seo rules `void seo` reports 60 rules in this category. What search engines need from the raw response: status codes, titles and descriptions in , self-referencing canonicals, one h1, crawlable links, Open Graph, icons, robots.txt and a sitemap with real dates. - `twitter-card` twitter:card missing — [seo/twitter-card](https://void-design.vercel.app/rules/seo/twitter-card) - `favicon` No crawlable favicon in a Google-supported format — [seo/favicon](https://void-design.vercel.app/rules/seo/favicon) - `apple-touch-icon` apple-touch-icon missing or not a 180×180 PNG — [seo/apple-touch-icon](https://void-design.vercel.app/rules/seo/apple-touch-icon) - `manifest` Web app manifest missing or incomplete — [seo/manifest](https://void-design.vercel.app/rules/seo/manifest) - `robots-txt-unreachable` robots.txt returns 5xx/429 or times out — [seo/robots-txt-unreachable](https://void-design.vercel.app/rules/seo/robots-txt-unreachable) - `robots-txt-missing` No robots.txt — [seo/robots-txt-missing](https://void-design.vercel.app/rules/seo/robots-txt-missing) - `robots-txt-invalid` robots.txt serves HTML, exceeds 500 KiB, or has unparseable lines — [seo/robots-txt-invalid](https://void-design.vercel.app/rules/seo/robots-txt-invalid) - `robots-blocks-all` robots.txt disallows the site for * / Googlebot / Bingbot — [seo/robots-blocks-all](https://void-design.vercel.app/rules/seo/robots-blocks-all) Detected by `void seo` and `void audit`. Explain it in a terminal: `void rules seo/theme-color`