Dulux Indonesia repainted canteen tables yellow to repel flies

In Indonesia's hot, humid climate, houseflies land freely on open school-canteen food, carrying pathogens responsible for diseases including typhoid, cholera and diarrhoea — a serious public-health problem in settings that can't afford enclosed, air-conditioned dining. The standard response is chemical: insecticide spraying, sticky traps, or netting, all of which require ongoing application, cost, and maintenance around food surfaces, and none of which address whether flies are drawn to the surface at all.

Dulux Indonesia and INNOCEAN ran a simple on-ground experiment — identical food placed on two otherwise identical tables, one painted bright yellow and one left unpainted — and found flies consistently avoided the yellow surface.

Repainted canteen furniture yellow, using flies' visual repulsion to make the surface itself the deterrent, with no ongoing spraying or traps.

Houseflies are repelled by yellow surfaces, so repainting tables made them avoid landing.

The fix was in the furniture itself, requiring no ongoing chemicals or maintenance.

A side-by-side pilot proved the effect before scaling to thousands of students.

Before adding a chemical or mechanical fix, change a property of the surface itself to make the unwanted behavior not happen there.

The pilot experiment confirmed yellow's fly-repelling effect on canteen surfaces, prompting a wider rollout to additional schools; more than five thousand students had eaten in yellow-painted canteens within two months of launch, with no chemical fly control needed in those spaces.