Is wearing a jalabiya with unusual colors and a noticeable wool cap considered part of the religion or Sunnah, especially given the disapproving looks from those who wear other types of clothing?

The fundamental principle regarding clothing is that a Muslim should wear what is customary in their society, as long as it does not violate Islamic law in terms of covering the 'awrah, avoiding 'isbal (letting one's garment hang below the ankles), arrogance, seeking fame, or imitating those whom we are forbidden to imitate. Muslim youth should not distinguish themselves in dress and customs except in ways that do not violate Islamic law. Rather, they should distinguish themselves by adhering to God's religion, inviting others to it with wisdom, and serving society. There is no religious impediment to wearing a suit or work clothes, provided they adhere to the aforementioned guidelines, as the matter is broad.