It was narrated from Umm 'Atiyyah that the Messenger of Allah (ﷺ) said:
'No deceased person should be mourned for more than three days, except a woman should mourn for her husband for four months and ten days, and she should not wear dyed clothes, except for a garment of 'Asb, and she should not wear kohl or perfume, except at the beginning of her purity, when she may apply a little Qust and Azfar.'"
English reference: Vol. 3, Book 10, Hadith 2087
Arabic reference: Book 10, Hadith 2165