"하얗게 지새운 밤" => A night I went completely sleepless. - 밤: night. - (밤을) 새우다: stay up through the night without sleep. - (밤을) 지새우다: an emphasized form of 새우다. It is also more poetic. - 하얗게: in white. "white" can signify a mental state of being awake, saturated with thoughts or worries, etc.

a night you could not get sleep well