User – there is absolutely no halachik obligation to wear black/navy and white; these are the identifying characteristics of the current day yeshiva world, but are not obligatory in halacha. Wearing a hat while davening or for shabbos is an obligation according to many poskim, but those who don’t have what to rely on.
What I meant is that the way a man dresses is a clear “statement” regarding how he associates himself. A man, especially under 40 (the yeshiva world adopted this universal mode of dress about 30 years ago) who wears colored shirts, light suits etc, is communicating that he sees himself in the “baalhabatish” world, or MO. I’m not saying this is right or wrong – I personally don’t have an opinion on the matter, but this is the current state of affairs.