diff --git a/core/themes/olivero/olivero.post_update.php b/core/themes/olivero/olivero.post_update.php
index 902824abab98d1010c660fb849aa5ff2f84e3da2..f033945e02be45f1a74e43d353c25f784c7f398f 100644
--- a/core/themes/olivero/olivero.post_update.php
+++ b/core/themes/olivero/olivero.post_update.php
@@ -6,10 +6,10 @@
  */
 
 /**
- * Implements hook_removed_post_updates().
+ * Sets the default `base_primary_color` value of Olivero's theme settings.
  */
-function olivero_removed_post_updates() {
-  return [
-    'olivero_post_update_add_olivero_primary_color' => '10.0.0',
-  ];
+function olivero_post_update_add_olivero_primary_color() {
+  \Drupal::configFactory()->getEditable('olivero.settings')
+    ->set('base_primary_color', '#1b9ae4')
+    ->save();
 }
diff --git a/core/themes/olivero/tests/src/Functional/Update/OliveroPostUpdateTest.php b/core/themes/olivero/tests/src/Functional/Update/OliveroPostUpdateTest.php
new file mode 100644
index 0000000000000000000000000000000000000000..38c1d29930d055c61e0780128946a088820f8ab2
--- /dev/null
+++ b/core/themes/olivero/tests/src/Functional/Update/OliveroPostUpdateTest.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace Drupal\Tests\olivero\Functional\Update;
+
+use Drupal\FunctionalTests\Update\UpdatePathTestBase;
+
+/**
+ * Tests the update path for Olivero.
+ *
+ * @group Update
+ */
+class OliveroPostUpdateTest extends UpdatePathTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setDatabaseDumpFiles() {
+    $this->databaseDumpFiles = [
+      __DIR__ . '/../../../../../../modules/system/tests/fixtures/update/drupal-9.4.0.filled.standard.php.gz',
+    ];
+  }
+
+  /**
+   * Tests update hook setting base primary color.
+   */
+  public function testOliveroPrimaryColorUpdate() {
+    $config = $this->config('olivero.settings');
+    $this->assertEmpty($config->get('base_primary_color'));
+
+    // Run updates.
+    $this->runUpdates();
+
+    $config = $this->config('olivero.settings');
+    $this->assertSame('#1b9ae4', $config->get('base_primary_color'));
+  }
+
+}