Does the jacket have to be worn in the "conventional" manner?
Why not try it as a sort of turban one day, around one leg the lext, as an armband after that etc etc etc until management is forced to add a clause specifying in legalese exactly how the jacket is to be worn.
Once they have done this, ask them if they have insurance for ill-fitting jackets preventing access to pockets containing mobile phones when emergency phone calls might occur and by this circumstance be missed.
Once this is done, request management to test every employee for colour-blindness - even secretarial staff who don't go near the ramp. You want to be sure everyone can actually see the yellow colour. Mention "xanthocyanopsis", that should have them diving for a dictionary.
After this, request the jackets be dry-cleaned every week to keep them in their high state of visibility. Ask management to provide additinal jackets to fill in for those away being cleaned.
Similarly request management to put emergency supplies of jackets at strategic locations in case someone loses a jacket during work.
Also request management to put a "Jacket-tracking" system in (satellite based) to permit simultaneous tracking of every employee/worker wearing a jacket on the airport to further enhance safety.
Ask the OHS supervisor to give weekly lectures on the benefits of wearing jackets, both at work and outside the workplace.
I'm sure you can think of more ways to make the management heartily sick of yellow safety jackets whilst having some fun at the same time. My feeling is the individual who first thought up this idea didn't have much else to do.