Wearing Black at the Time of Calamities is an Invalid Distinction

Question :

Is it permissible to wear a black garment for (mourning) the dead, in particular a deceased husband?

Answer:

Wearing black at the time of calamities is a distinction that is invalid, with no basis to it. When a person is afflicted by some calamity, he should do what the Islamic Law ordains, by saying: "Truly, to Allah we belong and truly, to Him we shall return. O Allah! Deliver me from my calamity and replace it with something better for me."

Because if she says that with faith and belief, then Allah, Most Glorified, Most High will deliver her from it and replace them. with something better. This happened to Umm Salamah, may Allah be pleased with her, when Abu Salamah, may Allah be pleased with him, her husband and cousin died. He was the most beloved of people to her, so she said this invocation. She said: "And I used to say to myself: 'Who is better than Abu Salamah?"" Then when her waiting period was over, the Prophet ﷺ proposed to her and he was better for her than Abu Salamah, may Allah be pleased with him.

Likewise, everyone who says this invocation with faith and belief, Allah, Most High will deliver him from his calamity and give him one better than her.

As for wearing special clothes, such as black garments and the like, there is no basis to this and it is something invalid and reprehensible.

Source:
Ibn 'Uthaimin
Fatawa Islamiyah, Vol. 6 Pages 102-103