I believe in some sections of cadet field craft (particularly blank firing) directing staff with patrols have to wear hi vis jackets for H&S reasons.
A little blue patch on a rank slide, particularly at night will not be noticeable.
Throw in the pink rucksacks & the multi-coloured bobble hats and the stealth bit of cadet fieldcraft become a bit of a token aspect.
However the best/most annoying bit when I was a cadet doing all the fieldcraft bits was the the contingent photographer who would often take a photo of us whilst in ambush positions waiting for the patrol to come past.
I don’t know which was more blinding - the trip flares or the Canon EOS flash system.
Anyhoo - we digress.