Amongst the Religious-Zionist community, like perhaps all communitites, students generally follow the intellectual perspective of their Rav.
In my yeshiva, Yeshivat Har Etzion, Rav Lichtenstein (Rosh Yeshiva) wears a suit as do rabbanim who made aliya from America. Israeli rabbanim and students are more likely to wear coloured trousers/shirts and any type of shoes or sandals.
Although the actual dress varies, the thinking behind the choice is similar. Each individual wears what they feel to be respectable clothing, befitting a ben torah.
A difference between more Charedi communities and more "modern" ones is that Charedi communities receive specific guidance from their leaders on the minutae of everyday life (Daas Torah), ranging from dress code to permissable cellphone model (Badatz give hechsherim to phones) . In the Dati Leumi world people are expected to make their own informed decisions and not rely on the example of their leaders for minor decisions.