Update app.py

app.py

@@ -124,7 +124,7 @@ def video_frame_callback(frame: av.VideoFrame) -> av.VideoFrame:
                                 output_text = output_text[:-1]   # Remove last character
                             else:
                                 output_text += ' '  # Add space
-    cv2.putText(img, output_text, (int(0.05 * w) , int(0.70 * h)), cv2.FONT_HERSHEY_PLAIN, 2, (255, 255, 255), 5)
+    cv2.putText(img, output_text, (int(0.05 * w) , int(0.70 * h)), cv2.FONT_HERSHEY_PLAIN, 2, (0, 0, 0), 5)