Having done job interviewing, by the time the short list of who will be interviewed for a job is reached, you have a list of candidates, who will all have reached similar levels of education and have similar experience, plus the occasional wild card.
The interview process is about probing experience and knowledge specific to the post advertised and whether that person has the personal aptitudes which you are looking for, enthusiasm for the work, or an enquiring mind could be important. One person might have work experience that is particularly relevant, which you, as another candidate for the job, would not know about. And the personal side will always come into it. Will the person fit in and contribute to the team. I have been in situations where one disruptive and difficult member of the team has caused endless problems.
I cannot envisage a situation where in the normal run of interviewing, someone would be preferred or rejected for any of the physical traits you mention, height, hair colour , size etc. It is not possible to say 'never' over anything, but it would be quite exceptional, and if known a justified reason for complaint.