diff --git a/layouts/partials/paige/style.html b/layouts/partials/paige/style.html
index bb1453cd..f7c4fed1 100644
--- a/layouts/partials/paige/style.html
+++ b/layouts/partials/paige/style.html
@@ -86,6 +86,8 @@ section.paige-content > blockquote p:last-of-type {
         {{ partial "paige/dark.css" . | safeCSS }}
     {{ else if eq . "light" }}
         {{ partial "paige/light.css" . | safeCSS }}
+    {{ else }}
+        {{ errorf "invalid color scheme: %q" . }}
     {{ end }}
 {{ else }}
     @media (prefers-color-scheme: dark) {