There is an undocumented function
RedirectTexture(texture1, texture2). I'll test if it works.
Lua Code:
RedirectTexture("EsoUI/Art/Inventory/newItem_icon.dds", "EsoUI/Art/Buttons/accept_up.dds")
RedirectTexture("EsoUI/Art/Inventory/inventory_stolenItem_icon.dds", "EsoUI/Art/Buttons/decline_up.dds")
EDIT:
It works.
