material color not changing

i have some problem. i am use this code

GetComponent<Renderer>().material.color = new Color(255,0,255,255);

Working but not what i want. look that.

Create new material but old one is still there. and gameobject using the old.

and then I used the following code

GetComponent<Renderer>().material.color.r = 50;

I got this error.

Assets/Script/Son.cs(32,53): error CS1612: Cannot modify a value type return value of `UnityEngine.Material.color'. Consider storing the value in a temporary variable

I do not know what to do.

Sorry for english :(.

Try using this

GetComponent<Renderer>().material.color = new Color(50, GetComponent<Renderer>().material.color.g, GetComponent<Renderer>().material.color.b, GetComponent<Renderer>().material.color.a);

up vote if this helped