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 {
@@ -56,6 +61,8 @@
   scopeLookupTable: string[][];
   // The object that applies the highlightings clangd sends.
   highlighter: Highlighter;
+  // The current color theme used for colorization.
+  private currentColorThemeName: string;
   // Any disposables that should be cleaned up when clangd crashes.
   private subscriptions: vscode.Disposable[] = [];
   fillClientCapabilities(capabilities: vscodelc.ClientCapabilities) {
@@ -70,9 +77,9 @@
   }
 
   async loadCurrentTheme() {
-    const themeRuleMatcher = new ThemeRuleMatcher(
-        await loadTheme(vscode.workspace.getConfiguration('workbench')
-                            .get<string>('colorTheme')));
+    this.currentColorThemeName = getCurrentThemeName();
+    const themeRuleMatcher =
+        new ThemeRuleMatcher(await loadTheme(this.currentColorThemeName));
     this.highlighter.initialize(themeRuleMatcher);
   }
 
@@ -91,6 +98,16 @@
     // highlighter being created.
     this.highlighter = new Highlighter(this.scopeLookupTable);
     this.subscriptions.push(vscode.Disposable.from(this.highlighter));
+    // Adds a listener to reload the theme when it changes.
+    this.subscriptions.push(
+        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();
     // Event handling for handling with TextDocuments/Editors lifetimes.
     this.subscriptions.push(vscode.window.onDidChangeVisibleTextEditors(