MyGizmo.cs

using UnityEngine;

using System.Collections;

public class MyGizmo : MonoBehaviour {

public Color _color = Color.yellow;

public float _radius = 0.2f;

void OnDrawGizmos()

{

Gizmos.color = _color;

Gizmos.DrawSphere(transform.position,_radius);   //DrawSphere --> 

}

}