They do now, I think
@eval_betty - and what's more, they do it on mopeds, wearing special vests, with the insignia "Deliveroo" written all over them. Apparently Nando's have found a way to retexture vests IRL! Who'da thunk it? All we need to do now, is explain to Bohemia Interactive Studios how to do this. And perhaps buy them some PERi-PERi Chicken thighs to nibble on while they're coding.
In the meantime however
@Stephen Allen - please, just understand... we (as in, the RPUK devs)
cannot solve this problem on the vanilla game with
any amount of magical voodoo, plain-paper textures, sticky-backed plastic, poster paints, Dulux, knitting needles, or holographic projection. Bohemia's handling of the vests (which bestow armour-effects to the players, whereas uniforms don't) is
totally different to the other uniform gear, and completely lacks the 'hooking-in' ability for external retexturing. It actually functions more like a weapon (which we are also unable to retexture, you'll have noticed), rather than a uniform. C'est la vie.
Until Bohemia change their methodology (which is about as likely as Nandos delivering prostitutes, tbh), there is zero chance of retexturing vests without using an addon mod (which is our policy to avoid, for reasons of balance, accessibility and overall fairness)
Also, we have found in the past that the line-of-thought which goes "Why do Bohemia do it this way? This is nuts?" is, whilst completely commonplace and regular, only really a recipe for a stomach ulcer and an early heart-attack. Hence we tend to just console ourselves with invoking the ubiquitous hashtag #becauseBIS and then get on with our lives as best we can. And eat plenty of chicken.
Hope this helps.
PS - other brands of spicy chicken are available. YMMV.