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");
    }));
}

}

  1. 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;
}

}

in the onvoiceresult method

void OnVoiceResult(string text) {
     if(text == Color.green){ mat.color = Color.green; }//mat is just the material of the gamobject you want to change just assign in the inspector.
     uiText.text = text;
}