How can I change the color of the cube with speech recognition ?

How can I change colour of cube with voice/speech. I have sample code with me

1) VoiceController using UnityEngine; using UnityEngine.UI;

public class VoiceController : MonoBehaviour {

 AndroidJavaObject activity;
 AndroidJavaObject plugin;

 public delegate void OnResultRecieved(string result);
 public static OnResultRecieved resultRecieved;

 private void Start() {
     InitPlugin();
 }

 void InitPlugin() {
     AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer");

     activity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity");
     
     activity.Call("runOnUiThread", new AndroidJavaRunnable(() => {
             plugin = new AndroidJavaObject(
             "com.example.matthew.plugin.VoiceBridge");
     }));

     activity.Call("runOnUiThread", new AndroidJavaRunnable(() => {
         plugin.Call("StartPlugin");
     }));
 }

 /// <summary>
 /// gets called via SendMessage from the android plugin GameObject must be called "VoiceController"
 /// </summary>
 /// <param name="recognizedText">recognizedText.</param>
 public void OnVoiceResult(string recognizedText) {
     Debug.Log(recognizedText);
     resultRecieved?.Invoke(recognizedText);
 }

 /// <summary>
 /// gets called via SendMessage from the android plugin
 /// </summary>
 /// <param name="error">Error.</param>
 public void OnErrorResult(string error) {
     Debug.Log(error);
 }

 public void GetSpeech() {
     // Calls the function from the jar file
     activity.Call("runOnUiThread", new AndroidJavaRunnable(() => {
         plugin.Call("StartSpeaking");
     }));
 }

}

2) VoiceTest using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEngine.UI;

[RequireComponent(typeof(VoiceController))] public class VoiceTest : MonoBehaviour {

 public Text uiText;

 VoiceController voiceController;

 public void GetSpeech() {
     voiceController.GetSpeech();
 }

 void Start() {
     voiceController = GetComponent<VoiceController>();
 }

 void OnEnable() {
     VoiceController.resultRecieved += OnVoiceResult;
 }

 void OnDisable() {
     VoiceController.resultRecieved -= OnVoiceResult;
 }

 void OnVoiceResult(string text) {
     uiText.text = text;
 }

}