Yitzy99,
What you are missing is that it is the uniform of the yeshiva today, it is irrelevant as to where you posit it came from. You are just trying to confound the issue.
Norman,
Learning the differences between binyan kal and binyan hi’fil does not change the fact that by dressing differently from the rest of the group, you are seperating your self from that group, be it consciously or sub-consciously. You want to discuss learning additional dikduk, fine, but that does not change the issue at hand.
Tzippi,
No one is excluding these people from Torah and invalidating them. The issue is are you identifying with a group and being part of it or do you wish to stand seperate and apart. The fact is that the norm, as accepted by the yeshiva as whole in many yeshivos is to wear white shirts. That is how the talmidim theselves dress. In most cases that I am aware of, from my own years in yeshiva as wells as my sons’ and nephews there is no letter that goes out and says wear white shirts, or we reccomend wearing such, rather, it is understood that the white shirt is the de facto uniform of yeshiva leit in those yeshivos.
There are yeshivas that are not that way and they too are wonderful yeshivos, this is one of the factors that go into selecting a yeshiva. NO not white shirt or not, rather will I be part of that group or will I chose to be outwardly and visibly different from the group by design.