How to get the component in a new class

Hey guys, here is the script:

 [System.Serializable]
 public class main
 {
     public GameObject Prefab;
     public Text Btn_Text;
     public Color color;
 }
 
 public class StoreManager : MonoBehaviour
 {
     //All the lists in the script
     [Header("All the lists")]
     public List<main> Main = new List<main>();
     //Ends here

I need to set the color of the gameobject prefab as the color of the color variable. when I use GetComponent it doesn't work. what can I do right now?

Any help would be appreciated