diff --git a/bundles/org.eclipse.e4.ui.css.swt.theme/src/org/eclipse/e4/ui/css/swt/internal/theme/ThemeEngine.java b/bundles/org.eclipse.e4.ui.css.swt.theme/src/org/eclipse/e4/ui/css/swt/internal/theme/ThemeEngine.java
index 42a7a0639a5..844bd280056 100644
--- a/bundles/org.eclipse.e4.ui.css.swt.theme/src/org/eclipse/e4/ui/css/swt/internal/theme/ThemeEngine.java
+++ b/bundles/org.eclipse.e4.ui.css.swt.theme/src/org/eclipse/e4/ui/css/swt/internal/theme/ThemeEngine.java
@@ -430,7 +430,12 @@ public void setTheme(String themeId, boolean restore) {
 				return;
 			}
 		}
-		// Theme not found (e.g. it was uninstalled); fall back to default
+		// In OS high-contrast mode keep the native OS colors instead of forcing a theme
+		if (display != null && display.getHighContrast()) {
+			ILog.of(ThemeEngine.class)
+					.warn("Theme '" + themeId + "' not found; using OS high contrast colors."); //$NON-NLS-1$ //$NON-NLS-2$
+			return;
+		}
 		ILog.of(ThemeEngine.class)
 				.warn("Theme '" + themeId + "' not found; falling back to default theme."); //$NON-NLS-1$ //$NON-NLS-2$
 		if (!E4_DEFAULT_THEME_ID.equals(themeId)) {
diff --git a/bundles/org.eclipse.e4.ui.workbench.swt/META-INF/MANIFEST.MF b/bundles/org.eclipse.e4.ui.workbench.swt/META-INF/MANIFEST.MF
index 37a7e9d1ea0..75d82205e69 100644
--- a/bundles/org.eclipse.e4.ui.workbench.swt/META-INF/MANIFEST.MF
+++ b/bundles/org.eclipse.e4.ui.workbench.swt/META-INF/MANIFEST.MF
@@ -1,7 +1,7 @@
 Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-SymbolicName: org.eclipse.e4.ui.workbench.swt;singleton:=true
-Bundle-Version: 0.18.100.qualifier
+Bundle-Version: 0.18.200.qualifier
 Bundle-Name: %pluginName
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
diff --git a/bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/E4Application.java b/bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/E4Application.java
index e544e7744b9..fe21a544490 100644
--- a/bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/E4Application.java
+++ b/bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/E4Application.java
@@ -324,8 +324,8 @@ private void setCSSContextVariables(IApplicationContext applicationContext, IEcl
 				context.set(E4Application.THEME_ID, DEFAULT_THEME_ID);
 			}
 		} else {
-			// Check if user has overridden the branding/command-line theme
-			String userThemeId = getProductScopedThemeId();
+			// Do not let a product/workspace default override the OS high-contrast theme
+			String userThemeId = highContrastMode ? null : getProductScopedThemeId();
 			if (userThemeId != null) {
 				context.set(E4Application.THEME_ID, userThemeId);
 			} else {