How change "halo" in a object when detect collision?

Question

I have an object that changes its color when it collides with another object, and decreases its size: gameObject.transform.localScale /= 2; but it has a white halo.

I want the halo to match my object's color. So when the object is a green color, so also the halo will be green as well. And if my object is blue, then the halo will be blue as well. Also, I want that when my object detect collision with other object, halo also decrease and I don't know how can I do it.

Code change color (blue, red or green) when I press the screen:

public class ChangeColor : MonoBehaviour {

    public Material[] materials;
    public Renderer rend;

    private int index = 1;

    // Use this for initialization
    void Start () {

        rend = GetComponent<Renderer> ();
        rend.enabled = true;

    }

    public void Update() {
        if (materials.Length == 0) {
            return;
        }
        if (Input.GetMouseButtonDown (0)) {
            index += 1;

            if (index == materials.Length + 1) {
                index = 1; 
            }
            print (index);

            rend.sharedMaterial = materials [index - 1];                        
        }
    }
}

I know use halo but programatically I don't know.

Answer 1

This Halo Component is accessible with a bit of work, let me demonstrate it with code.

Private void Start() {   
    SerializedObject haloComponent = new SerializedObject(this.gameObject.GetComponent("Halo"));
    haloComponent?.FindProperty("m_Color").colorValue = Color.Red;
}

There are some more things you can do but this is the way to get a reference to the Halo. Keep in mind GetComponent<> is searching for something that is Halo and GetComponent("Halo") is searching for something with the name Halo. Since the Component is named Halo it works like a charm. Try it out