Change object color (random) when start game

I want help for script to change object random color but when start open the game and when go the next level only and i don’t want this script working when restart level
i have this script but when restart level The color is changed

my script :

public void Start()

    gameObject.GetComponent<MeshRenderer>().material.color = Random.ColorHSV();


restart Script:

public void RestartGame()
    Scene thisScene = SceneManager.GetActiveScene();


any help please