Design can last up to 25 years and needs to be renewed every 5 years
If your design is unique in its appearance, not functionality, a design protection is the cheapest way of obtaining exclusivity.
Anytime you update your design, you should file a new design at the patent office.
Most of the patent offices only accept designs with even, black lines. Photos can also be accepted but for the sake of registration Black and White line drawing is the best.