2 variables holding Renderer.materials change at the same time...

In my scene I want to add the option to change the color of a material at runtime. However, I also want to remember the original color of the materials in case the user want's to cancel the action. At any given moment only ONE object can be selected. So I defined a static variable called SelectedObject, inside the class SelectedObjectClass (JS):

public class SelectedObjectClass
{
public static var SelectedObject : GameObject;
}

In another script I control the material color editing. When an object is selected I read the Renderer.materials to TWO private variables (JS):

    materials = SelectedObjectClass.SelectedObject.GetComponent.().materials;
    originalMaterials = SelectedObjectClass.SelectedObject.GetComponent.().materials;

These 2 lines are only called ONCE when the object is selected. When the user changes the color, I make the changes in the "materials" variable and I assign materials back to Renderer.materials to show the change. The problem is: it seems that if I edit the color of a material inside materials, the same happens to the color of the material inside originalMaterials... So when the user cancels the edit, even though I re-assign originalMaterials to Renderer.materials, the color does not change back to the original one.