diff --git a/config/sync/core.entity_form_display.node.etape.default.yml b/config/sync/core.entity_form_display.node.etape.default.yml
index e14ba0f..3b21aaa 100644
--- a/config/sync/core.entity_form_display.node.etape.default.yml
+++ b/config/sync/core.entity_form_display.node.etape.default.yml
@@ -147,7 +147,7 @@ third_party_settings:
       weight: 6
       format_type: fieldset
       format_settings:
-        classes: ''
+        classes: couleur
         show_empty_fields: true
         id: ''
         label_as_html: false