Problem with color c#

I`ve made a simple code, that changes tint color during the time, and it works fine when
line that changes color is like that: renderer.material.SetColor(“_TintColor”,Color.magenta);
But it works not right if i change color like this:

public class RenderColorTest : MonoBehaviour
{

public float Timer = 1f;
Color colorBlue;
// Use this for initialization
void Start () 
{
	colorBlue.r = 0;
	colorBlue.g = 105;
	colorBlue.b = 255;
	colorBlue.a = 128;

}

// Update is called once per frame
void Update () 
{
	Timer -= Time.deltaTime;
	if(Timer < 0)
		renderer.material.SetColor("_TintColor",colorBlue);
	
}

}

Thanks for any help!

This works for me:

using UnityEngine;
using System.Collections;

public class Colorchanger : MonoBehaviour {
    public float Timer = 10f;
    Color colorBlue = new Color(0, 0, 0, 0);
    // Use this for initialization
    void Start ()
    {
    colorBlue.r = 0;
    colorBlue.g = 105.0f;
    colorBlue.b = 255.0f;
    colorBlue.a = 128.0f;
     
    }
     
    // Update is called once per frame
    void Update ()
    {
    Timer -= Time.deltaTime;
    if(Timer < 0)
			//what I used to test
 	   // renderer.material.SetColor("_Color",colorBlue);
          renderer.material.SetColor("_TintColor",colorBlue);
    }
}