Use white header so Linolium logo contrasts properly

Author: amkram

mkdocs.yml

@@ -8,15 +8,15 @@ theme:
   palette:
     - media: "(prefers-color-scheme: light)"
       scheme: default
-      primary: indigo
-      accent: blue
+      primary: white
+      accent: indigo
       toggle:
         icon: material/weather-night
         name: Switch to dark mode
     - media: "(prefers-color-scheme: dark)"
       scheme: slate
-      primary: indigo
-      accent: blue
+      primary: black
+      accent: indigo
       toggle:
         icon: material/weather-sunny
         name: Switch to light mode