Red should be the colour for toilet cleaning equipment because these are high-risk areas. Blue is the colour for low-risk areas excluding food areas. There is another green colour that is the one for servicing food and bar use. And yellow is for washbasins, sinks, cabinets, and other washroom surfaces. Well, these are the four colour coding accepted universally. And this colour coding is significant in hospitals and other healthcare sites where hygiene standards are high.