--- a/src/Element/BaseSettings.php
+++ b/src/Element/BaseSettings.php
@@ -1272,7 +1272,10 @@ class BaseSettings extends FormElementBase {
     $id_prefix = implode('-', $parents);
     $element_state = static::getElementState($parents, $form_state);
     $state_color_indexes_key = $id_prefix . '__default_display_color_indexes';
-    $options_display_colors = $options['display']['colors'];
+    if (!isset($options['display']['colors']) || !is_array($options['display']['colors'])) {
+      $options['display']['colors'] = [];
+    }
+    $options_display_colors = $options['display']['colors'];
     if (!$element_state) {
       $element_state = $options;
       $options_display_colors_indexes = !empty($options_display_colors) ? array_keys($options_display_colors) : [];
@@ -1353,7 +1356,7 @@ class BaseSettings extends FormElementBase {
       ],
       '#operation' => 'add',
       '#element_state_indexes_key' => $state_color_indexes_key,
-      '#array_slicing_args' => ['offset' => 0, 'length' => -4],
+      '#array_slicing_args' => ['offset' => 0, 'length' => -5],
     ];
 
     $element['display']['color_changer'] = [
--- a/src/Form/ChartsConfigForm.php
+++ b/src/Form/ChartsConfigForm.php
@@ -200,9 +200,12 @@ class ChartsConfigForm extends ConfigFormBase {
     }
 
     // Process the default colors to remove unneeded data.
-    foreach ($settings['display']['colors'] as $color_index => $color_item) {
-      $settings['display']['colors'][$color_index] = $color_item['color'];
+    if (!is_array($settings['display']['colors'] ?? NULL)) {
+      $settings['display']['colors'] = [];
     }
+    foreach ($settings['display']['colors'] as $color_index => $color_item) {
+      $settings['display']['colors'][$color_index] = $color_item['color'];
+    }
 
     // Save the main settings.
     $config = $this->config('charts.settings');