Safety colour have their effect only if they are intensely saturated. If saturation is not intense and colours are not in the right place, they lose their effect.
White is symbol for cleanliness and order. White rings in the waste baskets (trash baskets) are encouraging people to put trash into baskets. White floor and white door surface have similar influence. White lines indicate several areas for different purposes (one-way traffic, moving aruon inside working space...).
It is a signal for caution, because it is most visible. It is used on outwardly projecting parts of machines and different things as a label or sign, also on different barriers, changes in floor level... Especially seen when combined with black.
Orange is the signal for attention and danger. It should be used as a marker for hazardous machinery (rotating wheels, moving levers ...). The interior of safety devices should also be coloured in orange for workers to remind them to keep them closed. This is particularly relevant for electrical and driving devices.
Red is the most intrusive of all and so it has always been associated with danger and the signal for fire protection.
The blue colour is a safety signal to "Watch out!" It is used for marking useless scaffolding and machinery parts that are out of service. It serves as the basis for various illicit tables with.
Green is the signal for safety and should be the color for symols, associated with security (rather than red in terms of the Red Cross, first aid in hospitals). As opposed to red is also a sign to move on (red is a sign for Stop).