diff --git a/GUI/View/SampleDesigner/LayerForm.cpp b/GUI/View/SampleDesigner/LayerForm.cpp
index 5012ade7b49d94a28fad022a50039f7a4d6fc1ba..310f0357b08f2e0b3a1589bca4aecbb6766ddc15 100644
--- a/GUI/View/SampleDesigner/LayerForm.cpp
+++ b/GUI/View/SampleDesigner/LayerForm.cpp
@@ -89,8 +89,7 @@ LayerForm::LayerForm(QWidget* parent, LayerItem* layerItem, SampleEditorControll
     }
 
     QColor bckgroundCol = m_layer->color();
-    setStyleSheet("CollapsibleGroupBox {background-color: " + bckgroundCol.name(QColor::HexRgb)
-                  + "}");
+    setStyleSheet("LayerForm {background-color: " + bckgroundCol.name(QColor::HexRgb) + "}");
 
     m_layout->addBoldRow("Material:", new MaterialInplaceForm(this, layerItem, ec));
     m_layout->addValue(m_layer->thickness());
diff --git a/GUI/View/Widget/GroupBoxes.cpp b/GUI/View/Widget/GroupBoxes.cpp
index 591149f78d05020326544cc66ac1f52070bec3ad..3591f7cbc581068f0bb6364ebe14797aa0a919dc 100644
--- a/GUI/View/Widget/GroupBoxes.cpp
+++ b/GUI/View/Widget/GroupBoxes.cpp
@@ -27,6 +27,9 @@
 StaticGroupBox::StaticGroupBox(const QString& title, QWidget* parent)
     : QWidget(parent)
 {
+    setVisible(true);
+    setObjectName("StaticGroupBox"); // stylesheet -> transparent background
+
     auto* layout = new QVBoxLayout;
     setLayout(layout);
     layout->setSpacing(0);
@@ -39,7 +42,6 @@ StaticGroupBox::StaticGroupBox(const QString& title, QWidget* parent)
 
     m_body = new QWidget;
     layout->addWidget(m_body);
-    m_body->setObjectName("ContentArea"); // stylesheet -> transparent background
 }
 
 //  ************************************************************************************************
@@ -49,6 +51,9 @@ StaticGroupBox::StaticGroupBox(const QString& title, QWidget* parent)
 CollapsibleGroupBox::CollapsibleGroupBox(const QString& title, QWidget* parent, bool& expanded)
     : QWidget(parent)
 {
+    setVisible(true);
+    setObjectName("CollapsibleGroupBox"); // stylesheet -> transparent background
+
     auto* layout = new QVBoxLayout;
     setLayout(layout);
     layout->setSpacing(0);
@@ -79,7 +84,6 @@ CollapsibleGroupBox::CollapsibleGroupBox(const QString& title, QWidget* parent,
 
     m_body = new QWidget(this);
     layout->addWidget(m_body);
-    m_body->setObjectName("ContentArea"); // stylesheet -> transparent background
     m_body->setVisible(expanded);
     m_toggleButton->setArrowType(expanded ? Qt::ArrowType::DownArrow : Qt::ArrowType::RightArrow);
 
diff --git a/GUI/styles/Base.stylesheet b/GUI/styles/Base.stylesheet
index 2b22e0b3b01c1f6dca11a85748945ebdf486578d..4fe796fc8af452c767cd844e423450a701dbbb49 100644
--- a/GUI/styles/Base.stylesheet
+++ b/GUI/styles/Base.stylesheet
@@ -27,10 +27,9 @@ QRadioButton::focus
 QRadioButton,
 QCheckBox,
 QLabel,
-QWidget#ContentArea,
-QWidget#GroupBoxTitleWidget,
+QWidget#StaticGroupBox,
+QWidget#CollapsibleGroupBox,
 QWidget#GroupBoxToggler,
-QWidget#ContentArea .QWidget,
 QScrollArea .QWidget,
 QTreeView::item .QWidget,
 QListView::item .QWidget