Change a color from shader using JS script

Hello;

have created a shader script here's a part of it

     Properties 
     {
 _SunColor("Sun Color of Light", Color) = (0.977612,0.9254484,0.882769,1)
     }

I'd like that the script would be like that :

 //
 var colorObject : GameObject;
 var theColor : Color;
 
 function Start () {
     theColor = colorObject.light.color;
 }
 
 function Update () {
     this.renderer.material.Sun_Color_of_Light = theColor;
 }
 //End of script

• The "colorObject" variable is a GameObject with Light (like direction light)

My question is how can I make the color that I've mentioned in my shader script being able to be changed with the variable "theColor"

Sorry if I wasn't very clear with my question

Thanks, your help would be great ;)