White is traditionally a sign of purity, cleanliness, and Godliness.
Not all missionaries wear white. To which missionaries are you refering?
It depends on what religion you are talking about, and what historical period, but missionaries have gone all over the world... of all races, but probably more white.
This depends on the church, organization, or denomination that they are missionaries for. It also depends on what they are doing. Missionaries who preach or establish churches typically wear nice clothing, such as suits or dresses. Misisonaries who do humanitarian service typically wear more casual clothing. Dress standards are often set by the organization or church that they are serving for. See the images under "Related Links" below for examples.
Missionary work in the Oregon country was not very successful because the Native Americans were very suspicious of the missionaries because of the diseases that were introduced by missionaries and white immigrants.
missionaries
Elijah White in 1842
Elijah White in 1842
Yes, you can wear white if you want to. Unless there are certain requirements to not wear white.
Hasidim do not wear white tights.
The name of the white cloths that Muslims wear is called Iran. Which is a piece of white cloths that men wear, and the ladies wear black or white.
They are called the Missionaries of Charity.
During weddings the bridesmaids generally do not wear white on their heads. The bride can wear white on her head however, she does not have to.