Changing sprite alpha on all prefab clones

I'm trying to change the alpha/transparency of all clones of the prefab. The transparency of the prefab itself changes correctly, but when I put multiple clones of the same prefab in the scene only one clone changes. The prefab is a sprite and the alpha is changed when a key is pressed in the PlayerController:

     //--TRANSPARENCY--//
     if (PlayerController.toggleSpirit) {
         if (!isLocked) {
             isSpirit = !isSpirit;
         }
         
         PlayerController.toggleSpirit = false;
     }
     
     if (isSpirit) {
         sr.color = new Color(1f, 1f, 1f, .5f);
     } else if (isSpirit == false) {
         sr.color = new Color(1f, 1f, 1f, 1f);
     }

The sr.color is getting the SpriteRenderer Component.