I'm a mechanical fitter by trade and work in the mining industry as a Workshop Supervisor Colour depends on where you are. Everyone across site (except for office workers) have to have reflective strips, regardless. Underground guys wear orange for obvious reasons. On the surface, it depends on the department and what the manager calls. I wear navy trousers with orange shirt, so do my guys, but the fabrication guys wear all navy as the orange shirts deteriorate fast due to the light given off from welding. weird, i know. Our Building Services dept (chippies, refrig mechs, plumbers and sparkies) wear light blue shirts with navy trousers. I dont know of any set 'code' for uniform colour, but it would depend on the business owner more than anything.