Why do we wear white on Rosh Hashanah?
Most people don’t wear white clothing on Rosh Hashanah, and these clothes are special for Yom Kippur.
The reason for this is that Yom Kippur is a day of atonement, and white indicates our freedom of sin.
However, some wear white even on Rosh Hashanah, the reason being that this is the first of the Ten Days of Repentence, and the beginning of the process whereby we are cleansed of sin.
At the same time, Rosh Hashanah is the Day of Judgment, and we wish to present ourselves before Hashem as being clean of all sin.