Henna is a flowering plant, which can be used to color hair and skin. I saw numerous people with henna designs on their hands, arms, and feet. It is often applied when attending a special event like a wedding.
Here is a photo of my arm just after I had a henna design applied. It took about five or six minutes for the adept designer to apply it. And, it lasted for about two weeks.
Henna can also be rinsed into the hair to give it this distinct color often seen on men, women, and children in India.