MGA did not have seat belts installed by the factory. MK-II cars did have the anchor points installed in the car, but not the belts. Some very late production cars even had anchor points for a shoulder harness installed at the factory.

Period style seat belts for the MGA would be "aricraft style" belts with a lift buckle and chrome plated hardware. As all seat belts would have been either dealer installed or aftermarket parts "back in the day", the color was most commonly black, regardless of interior colors. Other color belts were and are still available, but colors other than black are a matter of personal taste (may look odd in the MGA).

For more information on installing seat belts see Interior Tech.