When I worked in the NHS, our coats were far from white because we used to write on them, in magic marker, things like specimen numbers, doctors and nurses names, phone numbers etc. that we had to deal with queries about. I was always impressed that the laundry managed to get them pristine white again.

Of course this was just us sloppy men - female techs carried useful things like notebooks (paper) and biros.

And nowadays in the NHS you will be hard-pressed to spot a white coat - people wear ordinary clothes, scrubs, or nurses uniforms. At least that's my impression as a recent in-patient.

    > "our coats were white because we used to write on them"