Warning signs, Prohibitor signs and Mandatory signs
“Warning Signs are triangle with black on yellow and a black border, it warns of hazards.
Prohibitory Signs are red circle with oblique on white, it prohibits risky behavior.
Mandatory Signs are blue circle, white pictogram it indicates actions required to safeguard health and avoid injury.”
“Spot the shape, know the action: a triangle warns, a red circle forbids and a blue circle instructs. Follow signs accordingly.”