what identity do the colors of safety helmet represent ?

what identity do the colors of safety helmet represent ?
The colors of safety helmet:
Generally the safety helmet we often see can be divided into six color s: white, blue, yellow, green , camouflage and black series. Red series include red and wine red and the yellow series include both orange and pale yellow.
The colors of safety helmet represent different meanings:
The construction industry:
Leadership - wine red
Technicians - red
Safety supervision persons - white
Supervision or electrician - blue
Other construction persons - yellow
Thus, in the construction site, we can determine their identity from the colors of their safety helmet which can avoid some situations of embarrassment.
The oil system:
Managers - white
Safety surveillance - yellow
The operator - red

Notice:
Other industries:
The red safety helmet is suitable for explosive workplace.