Labcoats are traditionally white, the better to show spills and stains, minimize interactions with dyes, etc. more traditionally worn were dust jackets, which allowed chemists to wear a jacket which would hide stains (ah, we chemists do have such a wonderful attitude to safety...).
In the last few years, blue labcoats have been on the rise. These are polymer-based but non-flammable and hard wearing. However, these are used in chemical laboratories, not hospitals.
Is there an in-universe explanation for why a medical doctor (who would be potentially exposed to all sorts of hazards) would wear a lab jacket which would potentially hide stains?