Short answer
Wear modest, loose, clean clothes in plain or muted colours. Women cover the body and usually the hair; men wear long trousers and a top that covers the shoulders. Islam does not require any colour: black is common in some cultures, but it is not a religious rule.
Funeral clothes follow the normal dress rules, and since the janazah is a prayer, Muslims attending must cover what is required in prayer. Wearing black as a required sign of mourning has no basis in the sunnah, and Hanafi texts dislike displaying grief through dress beyond what the sharia allows.
The four schools agree on this.
Explanation
Funeral clothes in Islam follow the same rule as all clothes: cover what must be covered, keep it simple, and avoid display. Since the janazah is a prayer, Muslims attending should wear clean clothes they can pray in.
- Women: loose clothes that cover the arms and legs, a headscarf (non-Muslim guests can bring one for the prayer area), little or no makeup and no strong perfume.
- Men: long trousers, a shirt or top that covers the shoulders, and clean socks. A thobe, shalwar kameez or plain suit are all common.
- Colours: white, grey, navy, black or any muted colour. White is the colour the Prophet ﷺ praised for clothing in general, and it is the colour of the kafan.
- Shoes: easy to slip off for the prayer area, and fit for walking on uneven ground at the cemetery.
Is black required? No. Many cultures wear black for mourning, and others wear white. Islam does not tie mourning to a colour. What it limits is outward mourning for more than three days, except for a widow; see how long mourning lasts. A widow in iddah wears plain clothes without decoration, in any colour; see what a widow can do during iddah.
For non-Muslim guests: no one will judge small mistakes. Modest, plain clothes, and a scarf for women in the prayer area, are a kind gesture the family will notice. See attending a Muslim funeral.
The evidence
Quran, Surah Al-A'raaf 7:31
۞ يَٰبَنِىٓ ءَادَمَ خُذُوا۟ زِينَتَكُمْ عِندَ كُلِّ مَسْجِدٍۢ وَكُلُوا۟ وَٱشْرَبُوا۟ وَلَا تُسْرِفُوٓا۟ ۚ إِنَّهُۥ لَا يُحِبُّ ٱلْمُسْرِفِينَ ﴿٣١﴾
O children of Adam, take your adornment at every masjid, and eat and drink, but be not excessive. Indeed, He likes not those who commit excess.
Clean, decent clothes are the dress for every prayer, the janazah included.
Sunan Abi Dawud 4061
Grading to be checked... البسوا من ثيابكم البياض فإنها خير ثيابكم ...
"Wear white clothes, for they are the best of your clothes, and shroud your dead in them."
White is praised, but no colour is required for mourning.
Sahih al-Bukhari 1294
Sahih... ليس منا من لطم الخدود وشق الجيوب ...
"He is not one of us who slaps his cheeks and tears his clothes in grief."
Islam limits outward displays of mourning.
Where the ruling is recorded
- al-Hidaya, Kitab al-Salah, Bab Shurut al-Salah. What must be covered in prayer.
- Radd al-Muhtar (Ibn Abidin), Kitab al-Talaq, Fasl fi al-Hidad. The widow's mourning dress and the three-day limit for others.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.