I checked the PR code and I think I found the issue. nb.options.categories.tabPanelBackground color property seems to be not defined, so it returns white.
netbeans/platform/options.api/src/org/netbeans/modules/options/OptionsPanel.java: private Color getTabPanelBackground() { Color uiColor = UIManager.getColor("nb.options.categories.tabPanelBackground"); //NOI18N if (uiColor != null) { return uiColor; } if( useUIDefaultsColors() ) { // true for Metal or Nimbus only Color res = UIManager.getColor( "Tree.background" ); //NOI18N if( null == res ) res = Color.white; return new Color( res.getRGB() ); } return Color.white; } If I add in my app licationUIManager.put("nb.options.categories.tabPanelBackground", Color.ORANGE); the Options ribbon becomes orange. Le lundi 15 novembre 2021, 22:15:40 UTC+1, Jerome Lelasseux <lelass...@yahoo.com.invalid> a écrit : Sorry I meant FlatLaf Dark. I use the following in ModuleInstall::validate() NbPreferences.root().node("laf").put("laf", "com.formdev.flatlaf.FlatDarkLaf"); UIManager.installLookAndFeel(new UIManager.LookAndFeelInfo("FlatLaf Dark", FlatDarkLaf.class.getName())); I tried the 2 options mentionned in the PR (below), it had some effect but not on the Options white ribbon... -J-Dflatlaf.useWindowDecorations=false \ -J-Dflatlaf.menuBarEmbedded=false Le lundi 15 novembre 2021, 16:46:14 UTC+1, Neil C Smith <neilcsm...@apache.org> a écrit : On Sun, 14 Nov 2021 at 19:54, Jerome Lelasseux <lelass...@yahoo.com.invalid> wrote: > I made a new release of my Netbeans platform application (NB 12.5, > JDK11.0.13, DarkLaf) and I noticed that the Options ruban is now white (see > image attached). It was dark when I built the previous release using NB12.3 > (and it's also dark in the Options dialog of NB12.5 when using DarkLaf). > > I could not find any change in my code that could explain this. If someone > has an idea where I should search... What is DarkLaf? Darcula or FlatLaf Dark? How are you setting the Look and Feel? Some things changed in this area with https://github.com/apache/netbeans/pull/2872 that might be affected. Best wishes, Neil