My old and cynical view is 'does it matter'. I think it is more important that within a unit we all wear the same. I also work in a hole in the ground. As it happens CS95 is de rigeur. Everyone wears it. everyone happy, no problem. In the same hole in the ground is a different unit who wear blues - all of them wear it so they look uniform. In neither case is the quilaity of the work affected by the uniform worn.
I am a cheap bar steward and like that CS95 is issue so I do not have to buy No 2s. However, if a new Boss came in and decreed that we would return to blues, return we would. I think all this talk about supporting staff in operational theatres, feeling and looking 'punchy', looking like the Army and therefore more joint, is tripe to be frank. It is hardly an erosion of standards or ethos IMO.