CheckBox: fixed background of check boxes in JIDE CheckBoxTree (broken since commit dd8ab242fb)

CHANGELOG.md

@@ -16,6 +16,8 @@ FlatLaf Change Log
 - Fixed color of `<address>` tag in HTML text.
 - IntelliJ Themes: Fixed table header background when dragging column in "Dark
   Flat" and "Light Flat" themes.
+- CheckBox: Fixed background of check boxes in JIDE `CheckBoxTree`. (regression
+  in 1.0-rc2)
 
 
 ## 1.0-rc2

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatRadioButtonUI.java

@@ -123,7 +123,7 @@ public class FlatRadioButtonUI
 		// - if background was explicitly set to a non-UIResource color
 		if( !c.isOpaque() &&
 			((AbstractButton)c).isContentAreaFilled() &&
-			(c.getBackground() != defaultBackground) )
+			!defaultBackground.equals( c.getBackground() ) )
 		{
 			g.setColor( c.getBackground() );
 			g.fillRect( 0, 0, c.getWidth(), c.getHeight() );