[Help] can't change GUIText color in Unity 5.6

Hi everyone!

I am making game and I want to create a menu with some GUIText tagged as “Texto”. They have to change to yellow if the mouse is over the text and stay in white if the mouse is not.

So, I tried to use the next part of code in my script written in C# but nothing happens.

    void OnMouseEnter(GUIText otros)
    {
        if (otros.CompareTag("Texto"))
        {
            otros.color = Color.yellow;
        }
    }

    void OnMouseExit(GUIText otros)
    {
        if (otros.CompareTag("Texto"))
        {
            otros.color = Color.white;
        }
    }

Thanks for help and sorry for my english.

Pliz, anyone know whats is wrong in my code?