As a sign to differentiate between kovod shabbos and yomtov, Belzer chassidim wear white socks on yomtov. Many chassidic courts wear white socks on shabbos, but Belze maintains its tradition from Europe and chassidim wear black socks on shabbos.
Last erev Sukkos the Rebbe Shlita instructed chassidim to wear white socks on yomtov for those able to do so, explaining this adds to kovod yomtov, including chol hamoed. Chassidim explain the rebbe is stringent in maintaining kedushas yomtov during the days of chol hamoed as well.
(YWN – Israel Desk, Jerusalem)