Sunan an Nasai
3535
Sahih+2

It was narrated from Safiyyah bint Shaibah, from Umm Salamah, the wife of the Prophet, that the Prophet said:"The woman whose husband has died should not wear clothes that are dyed with safflower or red clay, and she should not use dye nor kohl

SahihAbu Ghuddah
SahihAl-Albani