diff -u b/modules/paragraphs_collection_demo/paragraphs_collection_demo.install b/modules/paragraphs_collection_demo/paragraphs_collection_demo.install
--- b/modules/paragraphs_collection_demo/paragraphs_collection_demo.install
+++ b/modules/paragraphs_collection_demo/paragraphs_collection_demo.install
@@ -82,11 +82,10 @@
     ],
     'style' => [
       'enabled' => TRUE,
-      'groups' => ['general_group'],
+      'groups' => ['general_group' => ['default' => '']],
     ],
   ]);
   $container->save();
-
 }
 
 /**
@@ -108,7 +107,7 @@
     'type' => 'container',
     'paragraphs_container_paragraphs' => [$style_text_paragraph],
   ]);
-  $style_paragraph->setBehaviorSettings('style', ['style' => 'paragraphs-green']);
+  $style_paragraph->setBehaviorSettings('style', ['styles' => ['general_group' => 'paragraphs-green']]);
   $style_paragraph->save();
   $paragraphs[] = $style_paragraph;
 
diff -u b/paragraphs_collection.services.yml b/paragraphs_collection.services.yml
--- b/paragraphs_collection.services.yml
+++ b/paragraphs_collection.services.yml
@@ -4,7 +4,7 @@
     arguments: ['@module_handler', '@string_translation', '@controller_resolver', '@cache.discovery', '@theme_handler', '@config.factory']
   paragraphs_collection.style_group_discovery:
     class: \Drupal\paragraphs_collection\StyleGroupDiscovery
-    arguments: ['@module_handler', '@cache.discovery', '@theme_handler', '@config.factory', '@paragraphs_collection.style_discovery']
+    arguments: ['@module_handler', '@string_translation', '@controller_resolver', '@cache.discovery', '@theme_handler', '@config.factory']
   paragraphs_collection.grid_layout_discovery:
     class: \Drupal\paragraphs_collection\GridLayoutDiscovery
     arguments: ['@module_handler', '@cache.discovery', '@theme_handler']
diff -u b/src/Plugin/paragraphs/Behavior/ParagraphsStylePlugin.php b/src/Plugin/paragraphs/Behavior/ParagraphsStylePlugin.php
--- b/src/Plugin/paragraphs/Behavior/ParagraphsStylePlugin.php
+++ b/src/Plugin/paragraphs/Behavior/ParagraphsStylePlugin.php
@@ -97,6 +97,7 @@
       if (isset($this->configuration['groups'][$group_id]['default'])) {
         $plugin_default = $this->configuration['groups'][$group_id]['default'];
       }
+      //debug($this->yamlStyleDiscovery->getStyleOptions());
       $form['style_wrapper']['styles'][$group_id] = [
         '#type' => 'select',
         '#title' => $this->t('%group Style', ['%group' => $this->yamlStyleGroupDiscovery->getGroupLabel($group_id)]),
@@ -149,7 +150,6 @@
     $form['groups'] = [
       '#type' => 'select',
       '#title' => $this->t('Style groups'),
-      '#required' => TRUE,
       '#multiple' => TRUE,
       '#options' => $this->yamlStyleGroupDiscovery->getStyleGroups(),
       '#description' => $this->t('Restrict available styles to a certain style group. Select none to allow all styles.'),
@@ -161,8 +161,7 @@
     ];
     // @todo: Remove getCompleteFormState() after https://www.drupal.org/project/drupal/issues/2798261.
     $group_key = ['behavior_plugins', $this->getPluginId(), 'settings', 'groups'];
-    $groups = $form_state->getCompleteFormState()
-      ->getValue($group_key, $this->configuration['groups']);
+    $groups = $form_state->getCompleteFormState()->getValue($group_key, $this->configuration['groups']);
     $form['groups_defaults'] = [
       '#type' => 'container',
       '#prefix' => '<div id="style-wrapper">',
reverted:
--- b/src/StyleGroupDiscovery.php
+++ /dev/null
@@ -1,136 +0,0 @@
-<?php
-
-namespace Drupal\paragraphs_collection;
-
-use Drupal\Core\Cache\CacheBackendInterface;
-use Drupal\Core\Config\ConfigFactoryInterface;
-use Drupal\Core\Discovery\YamlDiscovery;
-use Drupal\Core\Extension\ModuleHandlerInterface;
-use Drupal\Core\Extension\ThemeHandlerInterface;
-use Drupal\Core\StringTranslation\StringTranslationTrait;
-
-/**
- * Provides common helper methods for style group discovery.
- */
-class StyleGroupDiscovery implements StyleGroupDiscoveryInterface {
-
-  use StringTranslationTrait;
-
-  /**
-   * Collection of style groups with their definition.
-   *
-   * @var array
-   */
-  protected $groupCollection;
-
-  /**
-   * The module handler.
-   *
-   * @var \Drupal\Core\Extension\ModuleHandlerInterface
-   */
-  protected $moduleHandler;
-
-  /**
-   * Collection of styles with its definition.
-   *
-   * @var array
-   */
-  protected $stylesDiscovery;
-
-  /**
-   * The cache backend.
-   *
-   * @var \Drupal\Core\Cache\CacheBackendInterface
-   */
-  protected $cache;
-
-  /**
-   * The theme handler.
-   *
-   * @var \Drupal\Core\Extension\ThemeHandlerInterface
-   */
-  protected $themeHandler;
-
-  /**
-   * Contains the configuration object factory.
-   *
-   * @var \Drupal\Core\Config\ConfigFactoryInterface
-   */
-  protected $configFactory;
-
-  /**
-   * Constructs a new YamlStyleDiscovery.
-   *
-   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
-   *   The module handler.
-   * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
-   *   The cache backend.
-   * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
-   *   The theme handler.
-   * @param \Drupal\Core\Config\ConfigFactoryInterface $config
-   *   The configuration factory object.
-   */
-  public function __construct(ModuleHandlerInterface $module_handler, CacheBackendInterface $cache_backend, ThemeHandlerInterface $theme_handler, ConfigFactoryInterface $config, StyleDiscoveryInterface $style_discovery) {
-    $this->moduleHandler = $module_handler;
-    $this->themeHandler = $theme_handler;
-    $this->cache = $cache_backend;
-    $this->configFactory = $config;
-    $this->stylesDiscovery = $style_discovery;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getStyleGroups() {
-    $cache_id = 'paragraphs_collection_style_group';
-    if ($this->groupCollection !== NULL) {
-      return $this->groupCollection;
-    }
-    else if ($cached = $this->cache->get($cache_id)) {
-      $this->groupCollection = $cached->data;
-    }
-    else {
-      $yaml_discovery = $this->getYamlDiscovery();
-      $this->groupCollection = [];
-      foreach ($yaml_discovery->findAll() as $module => $groups) {
-        foreach ($groups as $group => $definition) {
-          if (empty($definition['label'])) {
-            throw new InvalidStyleException('The "label" of "' . $group . '" must be non-empty.');
-          }
-          $this->groupCollection[$group] = $this->t($definition['label']);
-        }
-      }
-      $this->cache->set($cache_id, $this->groupCollection);
-    }
-    return $this->groupCollection;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getGroupLabel($group_id) {
-    $groups = $this->getStyleGroups();
-    if (in_array($group_id, array_keys($groups))) {
-      return $groups[$group_id];
-    }
-    return NULL;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getGroupId($group_label) {
-    return strtolower(str_replace(' ', '_', $group_label));
-  }
-
-  /**
-   * Gets the YAML discovery.
-   *
-   * @return \Drupal\Core\Discovery\YamlDiscovery
-   *   The YAML discovery.
-   */
-  protected function getYamlDiscovery() {
-    return new YamlDiscovery('paragraphs.style_group', $this->moduleHandler->getModuleDirectories() + $this->themeHandler->getThemeDirectories());
-  }
-
-}
diff -u b/src/Tests/ParagraphsStylePluginTest.php b/src/Tests/ParagraphsStylePluginTest.php
--- b/src/Tests/ParagraphsStylePluginTest.php
+++ b/src/Tests/ParagraphsStylePluginTest.php
@@ -283,12 +283,12 @@
 
     // Add a node with paragraphs and check the available styles.
     $this->drupalGet('node/add/paragraphed_test');
-    $this->drupalPostAjaxForm(NULL, NULL, 'paragraphs_container_add_more');
+    $this->drupalPostAjaxForm(NULL, NULL, 'paragraphs_' . $paragraph_type . '_add_more');
     $options = $this->xpath('//*[contains(@class,"paragraphs-style")]/option');
     $this->assertEqual(2, count($options));
     $edit = [
       'title[0][value]' => 'global_settings',
-      'paragraphs[0][behavior_plugins][style][style_wrapper][style]' => 'bold'
+      'paragraphs[0][behavior_plugins][style][style_wrapper][styles][bold_test_group]' => 'bold'
     ];
     $this->drupalPostForm(NULL, $edit, 'Save');
     $this->assertRaw('paragraphs-behavior-style--bold');
@@ -297,6 +297,11 @@
       'behavior_plugins[style][enabled]' => TRUE,
       'behavior_plugins[style][settings][groups][]' => ['italic_test_group'],
     ];
+    $this->drupalPostAjaxForm('admin/structure/paragraphs_type/' . $paragraph_type, $edit, 'behavior_plugins[style][settings][groups][]');
+    $edit = [
+      'behavior_plugins[style][enabled]' => TRUE,
+      'behavior_plugins[style][settings][groups][]' => ['italic_test_group'],
+    ];
     $this->drupalPostForm(NULL, $edit, t('Save'));
 
     // Update global settings and enable two styles.
@@ -305,27 +310,22 @@
       'styles[italic][enabled]' => TRUE,
     ];
     $this->drupalPostForm(NULL, $edit, 'Save configuration');
- /*   $node = $this->getNodeByTitle('global_settings');
+    $node = $this->getNodeByTitle('global_settings');
     $this->drupalGet('node/' . $node->id());
     // Assert that the class of the plugin is not added if disabled.
     $this->assertNoRaw('paragraphs-behavior-style--bold');
     $this->clickLink('Edit');
     // Assert that only the two enabled styles are available.
     $options = $this->xpath('//*[contains(@class,"paragraphs-style")]/option');
-    $this->assertEqual(3, count($options));
+    $this->assertEqual(2, count($options));
     $this->assertEqual($options[0], '- Default -');
     $this->assertEqual($options[1], 'Italic');
 
-    // Check that styles are not shown in style config when disabled.
-    $edit = [
-      'behavior_plugins[style][settings][groups][]' => 'Italic Test Group'
-    ];
-    $this->drupalPostForm('admin/structure/paragraphs_type/' . $paragraph_type, $edit, 'Save');
     $this->drupalGet('admin/structure/paragraphs_type/' . $paragraph_type);
-    $options = $this->xpath('//*[contains(@name,"behavior_plugins[style][settings][defaults][italic_test_group]")]/option');
+    $options = $this->xpath('//*[contains(@name,"behavior_plugins[style][settings][groups_defaults][italic_test_group][default]")]/option');
     $this->assertEqual(2, count($options));
     $this->assertEqual($options[0], '- None -');
-    $this->assertEqual($options[1], 'Italic');*/
+    $this->assertEqual($options[1], 'Italic');
   }
 
   /**
only in patch2:
unchanged:
--- a/config/install/paragraphs.paragraphs_type.container.yml
+++ b/config/install/paragraphs.paragraphs_type.container.yml
@@ -12,3 +12,6 @@ description: 'Use <em>Container</em> to group paragraphs to apply a common style
 behavior_plugins:
   style:
     enabled: true
+    groups:
+      general_group:
+        default: ''
only in patch2:
unchanged:
--- a/paragraphs_collection.module
+++ b/paragraphs_collection.module
@@ -68,7 +68,7 @@ function paragraphs_collection_theme() {
  * * Implements hook_modules_installed().
  */
 function paragraphs_collection_modules_installed($modules) {
-  \Drupal::cache('discovery')->deleteMultiple(['paragraphs_collection_grid_layouts', 'paragraphs_collection_style']);
+  \Drupal::cache('discovery')->deleteMultiple(['paragraphs_collection_grid_layouts', 'paragraphs_collection_style', 'paragraphs_collection_style_group']);
 }
 
 /**
only in patch2:
unchanged:
--- a/src/StyleDiscovery.php
+++ b/src/StyleDiscovery.php
@@ -102,7 +102,7 @@ class StyleDiscovery implements StyleDiscoveryInterface {
     $enabled_styles = $this->configFactory->get('paragraphs_collection.settings')->get('enabled_styles');
     foreach ($style_collection as $style => $definition) {
       if (empty($enabled_styles) || in_array($style, $enabled_styles)) {
-        if ((empty($group) || in_array($group, $definition['groups']))) {
+        if (empty($group) || in_array($group, $definition['groups'])) {
           $options[$style] = $definition['title'];
         }
       }
only in patch2:
unchanged:
--- a/src/StyleDiscovery.php
+++ b/src/StyleGroupDiscovery.php
@@ -12,21 +12,13 @@ use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\Core\StringTranslation\TranslationInterface;
 
 /**
- * Provides common helper methods for style discovery.
- * @todo Create documentation for style discovery https://www.drupal.org/node/2837995
+ * Provides common helper methods for style group discovery.
  */
-class StyleDiscovery implements StyleDiscoveryInterface {
+class StyleGroupDiscovery implements StyleGroupDiscoveryInterface {
 
   use StringTranslationTrait;
 
   /**
-   * Collection of styles with its definition.
-   *
-   * @var array
-   */
-  protected $stylesCollection;
-
-  /**
    * Collection of style groups with their definition.
    *
    * @var array
@@ -96,90 +88,46 @@ class StyleDiscovery implements StyleDiscoveryInterface {
   /**
    * {@inheritdoc}
    */
-  public function getStyleOptions($group = '') {
-    $options = [];
-    $style_collection = $this->getStyles();
-    $enabled_styles = $this->configFactory->get('paragraphs_collection.settings')->get('enabled_styles');
-    foreach ($style_collection as $style => $definition) {
-      if (empty($enabled_styles) || in_array($style, $enabled_styles)) {
-        if ((empty($group) || in_array($group, $definition['groups']))) {
-          $options[$style] = $definition['title'];
-        }
-      }
-    };
-    uasort($options, 'strcasecmp');
-    return $options;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getStyles() {
-    $cache_id = 'paragraphs_collection_style';
-    if ($this->stylesCollection !== NULL) {
-      return $this->stylesCollection;
+  public function getStyleGroups() {
+    $cache_id = 'paragraphs_collection_style_group';
+    if ($this->groupCollection !== NULL) {
+      return $this->groupCollection;
     }
     else if ($cached = $this->cache->get($cache_id)) {
-      $this->stylesCollection = $cached->data;
+      $this->groupCollection = $cached->data;
     }
     else {
       $yaml_discovery = $this->getYamlDiscovery();
-      $this->stylesCollection = [];
-      foreach ($yaml_discovery->findAll() as $module => $styles) {
-        foreach ($styles as $style => $definition) {
-          if (empty($definition['title'])) {
-            throw new InvalidStyleException('The "title" of "' . $style . '" must be non-empty.');
-          }
-          $definition['title'] = $this->t($definition['title']);
-          if (!empty($definition['description'])) {
-            $definition['description'] = $this->t($definition['description']);
+      $this->groupCollection = [];
+      foreach ($yaml_discovery->findAll() as $module => $groups) {
+        foreach ($groups as $group => $definition) {
+          if (empty($definition['label'])) {
+            throw new InvalidStyleException('The "label" of "' . $group . '" must be non-empty.');
           }
-          $this->stylesCollection[$style] = ['name' => $style];
-          $this->stylesCollection[$style] += $definition + ['libraries' => []];
+          $this->groupCollection[$group] = $this->t($definition['label']);
         }
       }
-      $this->cache->set($cache_id, $this->stylesCollection);
+      $this->cache->set($cache_id, $this->groupCollection);
     }
-    return $this->stylesCollection;
+    return $this->groupCollection;
   }
 
   /**
    * {@inheritdoc}
    */
-  public function getStyle($style, $default = NULL) {
-    $styles = $this->getStyles();
-    $enabled_styles = $this->configFactory->get('paragraphs_collection.settings')->get('enabled_styles');
-    if (empty($enabled_styles) || in_array($style, $enabled_styles)) {
-      if (isset($styles[$style])) {
-        return $styles[$style];
-      }
-
-      if ($default && isset($styles[$default])) {
-        return $styles[$default];
-      }
+  public function getGroupLabel($group_id) {
+    $groups = $this->getStyleGroups();
+    if (in_array($group_id, array_keys($groups))) {
+      return $groups[$group_id];
     }
-
     return NULL;
   }
 
   /**
    * {@inheritdoc}
    */
-  public function getStyleGroups() {
-    if ($this->groupCollection !== NULL) {
-      return $this->groupCollection;
-    }
-    else if (!empty($styles = $this->getStyles())) {
-      foreach ($styles as $style => $definition) {
-        foreach ($definition['groups'] as $group) {
-          $this->groupCollection[$group] = $group;
-        }
-      }
-    }
-    else {
-      $this->groupCollection = [];
-    }
-    return $this->groupCollection;
+  public function getGroupId($group_label) {
+    return strtolower(str_replace(' ', '_', $group_label));
   }
 
   /**
@@ -189,15 +137,7 @@ class StyleDiscovery implements StyleDiscoveryInterface {
    *   The YAML discovery.
    */
   protected function getYamlDiscovery() {
-    return new YamlDiscovery('paragraphs.style', $this->moduleHandler->getModuleDirectories() + $this->themeHandler->getThemeDirectories());
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getLibraries($style) {
-    $collection = $this->getStyles();
-    return $collection[$style]['libraries'];
+    return new YamlDiscovery('paragraphs.style_group', $this->moduleHandler->getModuleDirectories() + $this->themeHandler->getThemeDirectories());
   }
 
 }