Cosmetics Structure

CosmeticsApplier.cs

public class CosmeticsApplier : MonoBehaviour
{
    public ItemType[] applyPriority;

    private void Start()
    {
        ApplySelectedItems();
    }

    private void ApplySelectedItems()
    {
        List<ItemBase> selectedItems = FindObjectOfType<ItemManager>().GetAllSelectedItems();

        //Apply priority first
        foreach(ItemType priorityType in applyPriority)
        {
            for(int i = 0; i < selectedItems.Count; i++)
            {
                if(selectedItems[i].itemType == priorityType)
                {
                    selectedItems[i].Apply(gameObject);
                    selectedItems.RemoveAt(i);
                    break;
                }
            }
        }

        //Apply the rest here
        foreach(ItemBase item in selectedItems)
        {
            item.Apply(gameObject);
        }
    }
}

ItemBase.cs

public abstract class ItemBase : ScriptableObject
{
    public int itemID = -1;
    [HideInInspector] public ItemType itemType;

    protected ItemBase(ItemType _itemType)
    {
        itemType = _itemType;
    }

    public abstract void Apply(GameObject player);
}

ItemColor.cs

[CreateAssetMenu(fileName = "NewColor", menuName = "Player Items/New Color")]
public class ItemColor : ItemBase
{
    public Color color;

    public ItemColor() : base(ItemType.Color) { }

    public override void Apply(GameObject player)
    {
        SpriteRenderer spriteRenderer = player.FindComponentInChildWithTag<SpriteRenderer>("Shape");
        spriteRenderer.color = color;
    }
}

ItemShape.cs

[CreateAssetMenu(fileName = "NewShape", menuName = "Player Items/New Shape")]
public class ItemShape : ItemBase
{
    public GameObject shape;

    public ItemShape() : base(ItemType.Shape) { }

    public override void Apply(GameObject player)
    {
        Instantiate(shape, player.transform);
    }
}