I too dress up my doctors, except that I dress them in blues. On occasion I dress my villagers up according to family, but usually according to age as follows:
All those who are above the age that the women can have babies are dressed in red (except VV1). Older villagers with a higher title (or in VV1 just older elders), who I've given into retirement get to wear white or black.
Then the remaining villagers are sometimes dressed according to jobs, &/or by age in groups. This helps me to see quickly if I have a lot of trained villagers or younger ones who are just starting out.