diff --git a/clang-tools-extra/clangd/clients/clangd-vscode/src/semantic-highlighting.ts b/clang-tools-extra/clangd/clients/clangd-vscode/src/semantic-highlighting.ts
--- a/clang-tools-extra/clangd/clients/clangd-vscode/src/semantic-highlighting.ts
+++ b/clang-tools-extra/clangd/clients/clangd-vscode/src/semantic-highlighting.ts
@@ -5,6 +5,11 @@
 import * as vscodelc from 'vscode-languageclient';
 import * as vscodelct from 'vscode-languageserver-types';
 
+function getCurrentThemeName() {
+  return vscode.workspace.getConfiguration('workbench')
+      .get<string>('colorTheme');
+}
+
 // Parameters for the semantic highlighting (server-side) push notification.
 // Mirrors the structure in the semantic highlighting proposal for LSP.
 interface SemanticHighlightingParams {
@@ -49,6 +54,10 @@
   scopeLookupTable: string[][];
   // The rules for the current theme.
   themeRuleMatcher: ThemeRuleMatcher;
+  // The current color theme used for colorization.
+  currentColorThemeName: string;
+  // Disposable that should be cleaned up.
+  disposable: vscode.Disposable;
   fillClientCapabilities(capabilities: vscodelc.ClientCapabilities) {
     // Extend the ClientCapabilities type and add semantic highlighting
     // capability to the object.
@@ -61,9 +70,9 @@
   }
 
   async loadCurrentTheme() {
-    this.themeRuleMatcher = new ThemeRuleMatcher(
-        await loadTheme(vscode.workspace.getConfiguration('workbench')
-                            .get<string>('colorTheme')));
+    this.currentColorThemeName = getCurrentThemeName();
+    this.themeRuleMatcher =
+        new ThemeRuleMatcher(await loadTheme(this.currentColorThemeName));
   }
 
   initialize(capabilities: vscodelc.ServerCapabilities,
@@ -76,6 +85,14 @@
     if (!serverCapabilities.semanticHighlighting)
       return;
     this.scopeLookupTable = serverCapabilities.semanticHighlighting.scopes;
+    this.disposable = vscode.workspace.onDidChangeConfiguration((conf) => {
+      if (!conf.affectsConfiguration('workbench'))
+        // Configuration could not have affected the current colorTheme.
+        return;
+      const newColorTheme = getCurrentThemeName();
+      if (newColorTheme != this.currentColorThemeName)
+        this.loadCurrentTheme();
+    });
     this.loadCurrentTheme();
   }