Kashaya means red ochre and vastra means clothing. The use of red ochre is very old and has been associated with Hinduism and philosophy form very early times. Ochre is believed to the color of nivritti (non-attachment) in Hindu religion. The use of Kashaya Vastra indicates either that the user has attained non-attachment or that it helps those who wish to develop this quality.
In the prehistoric period, people used to apply red ochre to the dead before burying them. The presence of objects in grave indicates that they believed in life after death. Red ochre being the color of blood was also perhaps thought to give life to the dead, rejuvenation for the journey to next life. The use of red ochre is thus connected with the eschatological beliefs of early communities.
Red ochre is very similar to the color of vermilion, which too has had a long history of use in religious practices and beliefs of the people. Vermilion is applied to the images of deities. Even now, married women in India apply it to the parting of their hair as a mark of good fortune and being blessed by the protective presence of their husbands. The custom goes back to the Early Harappan times (2800-2600 BCE) as evidenced by the discovery in excavations of some terracotta female figurines found from Naushahro and Mehrgarh (both in Pakistan now). Thus the use of Kashaya has come down to us through the ages.
Kashaya Vastram have a special significance in Hindu religion. As per Hindu belief, Goddess Parvati colored her white cloth with blood and gave it to Gorakshanatha as a blessing. Thus clothing of this color is treated as the dictum of the Goddess and as a gift for sannyasins (those who have renounce the world). So, all sannyasins wear clothing of this color. Hindu scriptures have given a thought to the qualities of colors also. Accordingly, every color and hue has it s own significance, has some effect on the users and some religious meaning too.
Apart from its religious significance, this particular color has some practical aspects. First, it is easy to prepare because a soil of that color is easily available in all parts of India; second, it shows dirt quickly, so the user has to be particular about is cleanliness; third, it is not an attractive color for ordinary eyes, thus preventing young sannyasins from appearing attractive to women. Further it made sannyasins stand out in a big gathering of people; this was a requirement since they had a special position in society. Even today the tradition is honored.