Riyad Us-Saliheen (Gardens of the Righteous)

Chapter 365
Prohibition of Wearing Saffron-Colored Dress

1798. Anas (May Allah be pleased with him) said: The Prophet (PBUH) prohibited men from wearing saffron-dyed clothes.
[Al-Bukhari and Muslim].

1799. `Abdullah bin `Amr bin Al-`As (May Allah be pleased with them) said: The Prophet (PBUH) saw me dressed in two saffron-coloured garments and asked, "Has your mother commanded you to wear these?'' I asked him, "Shall I wash them out?'' He replied, "You had better set them to fire.''

Another narration is: "These are garments of the disbelievers. So do not wear them.''
[Muslim].

Commentary:  Saffron and safflower  are plants with a bright orange-yellow colour. Their use is forbidden because this colour is generally used by women and disbelievers, and men should show no resemblance to women and disbelievers in their dress.