Yeshivish is the “lvush.” A person’s pnimious would determine how frum they are. The two dont always go together. The yeshivish person can go around wearing black and white and be yeshivish even though when he goes on vacation he doesnt act so frum yet he still looks yeshivish…Frum is the person’s inside, how the person acts in things bein adam lamakom middos,davening,yiras shamayim etc. he may not look so yeshivish but can be a way better person.