ISO 9547:2005 documents prescribe the code of practice for safety colours and safety signs. The purpose of safety colours and safety sign is to draw attention rapidly to objects and situation that affects safety and health. As per ISO Standard the safety colours, safety sign is in four colours – 
Red, Yellow, Green & Blue  Red indicates the Fire Signs comply in rectangular shape with red background, white border, white text and white symbol.  Prohibition signs are in white background with red circular band, black graphical symbol, and white border. Green indicates the Safety Signs which is in square shape with green background, white border, white text & symbols. Yellow indicates the warnings and are in triangle shape in yellow background, black triangle band border, black graphical symbols. Blue means Mandatory signs are in circular with blue Background, white text & symbol.