diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatSliderUI.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatSliderUI.java
index 645df95d..2d4526e6 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatSliderUI.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatSliderUI.java
@@ -81,6 +81,16 @@ public class FlatSliderUI
 		focusColor = UIManager.getColor( "Component.focusColor" );
 	}
 
+	@Override
+	protected void uninstallDefaults( JSlider slider ) {
+		super.uninstallDefaults( slider );
+
+		trackColor = null;
+		thumbColor = null;
+		disabledForeground = null;
+		focusColor = null;
+	}
+
 	@Override
 	public Dimension getPreferredHorizontalSize() {
 		return UIScale.scale( super.getPreferredHorizontalSize() );
diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTextAreaUI.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTextAreaUI.java
index 61cbf929..078200d4 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTextAreaUI.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTextAreaUI.java
@@ -53,6 +53,14 @@ public class FlatTextAreaUI
 		inactiveBackground = UIManager.getColor( "TextArea.inactiveBackground" );
 	}
 
+	@Override
+	protected void uninstallDefaults() {
+		super.uninstallDefaults();
+
+		disabledBackground = null;
+		inactiveBackground = null;
+	}
+
 	@Override
 	protected void paintBackground( Graphics g ) {
 		JTextComponent c = getComponent();