 Green is used for its traditional association with Islam, and the adaptation of the red envelope is based on the Muslim custom of "sadaqah", or voluntary charity.This is not necessarily true as envelopes of any or multi colors are available with contemporary designs incorporated.While present in the Qur'an, "sadaqah" is much less formally established than the sometimes similar practice of "zakat", and in many cultures this takes a form closer to gift-giving and generosity among friends than charity in the strict sense, i.e.