The ventilation stripes used on Apple products from 1984 to 1990 were part of a design language developed by Frog Design called Snow White.
“The Snow White design language was an industrial design language developed by Frog Design, founded by Hartmut Esslinger. It was used by Apple Computer from 1984 to 1990. It is characterised by vertical and horizontal stripes acting as decoration and occasionally ventilation, as well as creating the illusion of the computer enclosure being smaller than it actually is.”