JTabbedPaneのタブエリア背景色などをテスト

UIManager.put("TabbedPane.shadow",                Color.GRAY);
UIManager.put("TabbedPane.darkShadow",            Color.GRAY);
UIManager.put("TabbedPane.light",                 Color.GRAY);
UIManager.put("TabbedPane.highlight",             Color.GRAY);
UIManager.put("TabbedPane.tabAreaBackground",     Color.GRAY);
UIManager.put("TabbedPane.unselectedBackground",  Color.GRAY);
UIManager.put("TabbedPane.background",            Color.GRAY);
UIManager.put("TabbedPane.foreground",            Color.WHITE);
UIManager.put("TabbedPane.focus",                 Color.WHITE);
UIManager.put("TabbedPane.contentAreaColor",      Color.WHITE);
UIManager.put("TabbedPane.selected",              Color.WHITE);
UIManager.put("TabbedPane.selectHighlight",       Color.WHITE);
// UIManager.put("TabbedPane.borderHighlightColor",  Color.WHITE);
// Maybe typo but defined in MetalTabbedPaneUI
UIManager.put("TabbedPane.borderHightlightColor",  Color.WHITE);