Enforce custom colours when no theme is specified

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@fwdekker/template",
-    "version": "3.4.0",
+    "version": "3.4.1",
     "description": "The base template for pages on fwdekker.com.",
     "author": "Florine W. Dekker",
     "license": "MIT",

src/main/css/snippets/colors.css

@@ -1,5 +1,6 @@
 /* pico.css overrides, based on https://picocss.com/docs/customization.html */
 .fwd-nav,
+:root:not([data-theme]),
 :root[data-theme="light"] {
     --primary: rgb(0, 51, 204) !important;
     --primary-hover: rgb(0, 61, 245) !important;