"Celebration of Holi is meaningless without colours, but chemical colours may lead to severe complications. If the colours contain harmful chemical compounds such as oxides, metal, glass particles and substances used as a base in textile dyes, they could be extremely dangerous," says Anup Dhir, chief cosmetic surgeon, Indraprastha Apollo Hospital.
According to doctors, chemical colours have solvents such as tetrathyline, lead, benzene and aromatic compounds that can lead to dry skin. Dark colours like red, black and green have a high content of mercury sulphite, lead oxide and copper sulphate, which could cause skin cancer.
"Many are not aware of the harm chemical colours can cause. You may also develop rashes and allergy, hair could turn brittle and dry if not washed immediately after the colour is applied," Dhir said.
The week that follows Holi typically sees a spurt in certain medical conditions -- rashes and allergies, mostly in children and young adults, rise by almost 40 percent.
"Many tend to use greasy colours and dyes for the sheer fun of it. The reaction to such chemicals usually occurs two to three hours after coming in contact with them. The problem gets aggravated if one uses soaps, detergents and kerosene to remove the stubborn colours," D.J.S Tula, consultant plastic surgeon at Delhi's B.L.K. Hospital, told IANS.
Preparing organic colours at home is one option to keep away from this problem.
"If one wants to enjoy Holi without the risk posed by chemical colours, try home-made natural colours like haldi which give the yellow colour; it can be mixed with besan or gram flour to increase volume. Flowers like marigold or yellow chrysanthemums can also be crushed to get yellow colour. Henna and leaves of gulmohar can also be dried and powered to get a nice green, and dried rose petals can be substituted for red," says Preeti Banzal, a home-maker.
Banzal, who prepares homemade colours on order from apartment-dwellers near her house in east Delhi, said dried flowers available in the market can be soaked overnight or boiled to get saffron colour. Semul, also called red silk cotton, gives red colour.
The herbal and organic colours, which are made from extracts of flowers, tree barks and leaves, do not cause any harm when in contact with the skin, and are in high demand in the market.
"We offer organic colours which are non-toxic and skin-friendly, scented gulabari which is soft and smooth. It comes in five colours, with essential oil aromas like lemongrass, citronella and orange," said Mohit Taneja of Ebagsfull.com, an online portal.
The danger, however, lies not just in colours: Water balloons thrown haphazardly can potentially harm the eyes and cause chemical conjunctivitis, corneal abrasion (scratch in the cornea) and corneal burns.
"Use of synthetic colours made of chemicals pose a great threat to one's eyes. Exposure to chemicals can result in eye allergy, temporary blindness and conjunctivitis (pink eye). Therefore, when somebody is spraying water colours on your face, keep your eyes shut," says Sanjay Dhawan, additional director, ophthalmology department, Fortis Healthcare.
Ophthalmologists also warn people wearing contact lenses to desist from wearing them if there is a possibility of being smeared with colour.
"Avoid wearing contact lenses; use ordinary plastic glasses. Colour can come between your eye and lens, resulting in infection and in some cases, eye damage," Dhawan added.
Doctors say that despite all the warnings that are issued every year, there are cases of accidents happening.
"Youngsters pay no need to what doctors or older people tell them. If only wild plans and pranks are avoided, the risk of accidents would reduce," Tula said.