clean install

web/core/themes/olivero/olivero.post_update.php

@@ -0,0 +1,15 @@
+<?php
+
+/**
+ * @file
+ * Post update functions for Olivero.
+ */
+
+/**
+ * Sets the default `base_primary_color` value of Olivero's theme settings.
+ */
+function olivero_post_update_add_olivero_primary_color() {
+  \Drupal::configFactory()->getEditable('olivero.settings')
+    ->set('base_primary_color', '#1b9ae4')
+    ->save();
+}