diff --git a/lib/internal/util/inspect.js b/lib/internal/util/inspect.js
index 113ee6c9532f6c..87bf3435f96067 100644
--- a/lib/internal/util/inspect.js
+++ b/lib/internal/util/inspect.js
@@ -473,7 +473,8 @@ function stylizeWithColor(str, styleType) {
   const style = inspect.styles[styleType];
   if (style !== undefined) {
     const color = inspect.colors[style];
-    return `\u001b[${color[0]}m${str}\u001b[${color[1]}m`;
+    if (color !== undefined)
+      return `\u001b[${color[0]}m${str}\u001b[${color[1]}m`;
   }
   return str;
 }
diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js
index 5aea50ba1d1c30..2c7a3a96fa93d2 100644
--- a/test/parallel/test-util-inspect.js
+++ b/test/parallel/test-util-inspect.js
@@ -2240,6 +2240,12 @@ assert.strictEqual(
     assert.deepStrictEqual(inspect.colors[bgColor], [40 + i, 49]);
     assert.deepStrictEqual(inspect.colors[`${bgColor}Bright`], [100 + i, 49]);
   });
+
+  // Unknown colors are handled gracefully:
+  const stringStyle = inspect.styles.string;
+  inspect.styles.string = 'UNKNOWN';
+  assert.strictEqual(inspect('foobar', { colors: true }), "'foobar'");
+  inspect.styles.string = stringStyle;
 }
 
 assert.strictEqual(