We are a "High Viz Free Zone" and seem to be the only business in NZ who hasn't succumbed to this nonsense.

We have two types of contractors. Those that have a "permit to work" which gives them total free range and no need to identify them. The others must be accompanied by a staff member at all times.

How tasteless to stick guests in a high Viz. Urk!!! You wouldn't do it at home. Why do it at work. Our guests are accompanied by a host at all times.

We do have an underlying principle that we treat contractors (including on-hire agency workers) in exactly the same way as we treat our own staff. Same expectations, same access to facilities (including cafe), same dress expectations. Same Same!

Hi Michael,

We have an electronic sign in system on our reception that allows us to see who is on site at any one time. Unfortunately there are ways of getting on to site without passing through reception so we have recently introduced lanyards that are given out during site inductions and allow us to immediately recognise if a subbie has brought additional workers onto site without going through the induction process.

So far so good.

I echo Andrew's comments but ask the question "Why is Hi Vis clothing required?". I regard PPE as an admission of failure unless it can be demonstrated to be the only solution. That can result in some creative arguments leading to, for example, segregation of vehicles and people on larger sites, either spatially or by time.
In relation to Hi Vis generally, there is research showing it is of limited value under some circumstances and, in some cases, can act to cause confusion. For example, a worker may be unable to get the right depth of field when looking at a busy worksite at night due to so many reflective strips and colours moving.
Maybe move the discussion from Hi Vis as PPE to uniforms for workers with company names and/or badges printed onto jackets, Tee or long-sleeve shirts that are also Hi Vis? Pride in who workers work for?
Perhaps an article for Safeguard magazine that is research-based and informed by some good case studies?

I'm going to buck the trend here and say there's no problem doing that, as long as you explain the requirement properly to the contractor/visitor. Had exactly that scenario in a previous life - employees wore fluoro yellow hi-viz and visitors / contractors wore orange. Was successful because the employees then new that anyone in orange was not a "regular" and was also a potential hazard (even when an escorted visitor). And in the case of contractors, depending on the job they were doing, by differentiating the colour of Hi-viz, employees could make an instant assessment of whether or not the contractor was compliant with our other PPE requirements (hardhat, glasses etc.)
Yes in an ideal world PPE could be seen as an admission of failure or limited value, however there are circumstances where regardless of what you think, you have no choice e.g. corporate standards. Suck it and see, Michael!

@Jono Johnson
We do just that - our workers wear orange but we supply visitors and visiting contractors with yellow hi-vis vests with "VISITOR" printed in bold on the back. This generally works well and gives our forklift operators in particular a heads-up. We've just had to instruct our office staff not to wear the visitor's vests as this just confuses the issue.

Ports of Auckland used to have different colours of hi-viz vests for different functions across the business, as well as clearly labelled VISITOR hi-viz vests. That meant the only remaining h--viz colour left for fire wardens was fluro pink, which the mainly male workforce clearly did not want to wear every day. The mostly male fire wardens also complained loudly at being required to wear a fluro pink hi-viz vest, even just for the short and infrequent experiences of fire evacuation (thankfully only drills and smoke detectors set off by burnt toast and food remnants in kitchen ovens!).

A further useful identifier was used in addition to hi-viz vests. Workers were required to wear hard hats in that environment, so visitors and newbies (first 6 months, I think) wore white hard hats to inform others in the area that they may not be as familiar with the hazards and risks so their workmates could keep an eye out for their safety. In addition, with manufacturer recommendations to change hard hats every two years to prevent deterioration of their protective function, an orderly system was used to rotate a series of colours, with two colours being considered 'current' at any given time.

This colour system made it easy to identify hard hats that might be too old (i.e., UV exposure, wear, etc, as per manufacturer recommendations) to reliably provide adequate worker protection so they could be changed out for new ones.

Pink would be a great colour to use. Unfortunately there is nothing as fragile on most high risk sites as a male ego. I have seen contractors turn down work rather than wear pink on a construction site.

I have been in places where Pink hi-viz vests were used for visitors. Apparently they weren't as "accidently taken away" as much as other colours.

Unfortunately pink is not officially day-rated hi vis.