get shader unity c#
using UnityEngine;
public class Example : MonoBehaviour
{
    // Create a material from code
    void Start()
    {
        // Create a material with transparent diffuse shader
        Material material = new Material(Shader.Find("Transparent/Diffuse"));
        material.color = Color.green;
        // assign the material to the renderer
        GetComponent<Renderer>().material = material;
    }
}