Kalamezhuthu is a ritualistic art practiced in temples to worship and propitiate the gods like Ayyappa, Bhadrakali and Vettakkorumakan. In this ritual, the performer draws a Kalam or a huge picture with coloured powder on the floor.

The coloured powders used for the kalam are prepared from natural products only. The pigments are extracted from plants - rice flour (white), charcoal powder (black), turmeric powder (yellow), powdered green leaves (green), and a mixture of turmeric powder and lime (red). It often takes more than two hours to finish a kalam drawing with appealing perfection.

The figures drawn usually have an expression of anger, and other emotions. Decorations like a canopy of palm fronds, garlands of red hibiscus flowers and thulasi or Ocimum leaves are hung above the kalam. In the climax of the ritual, the drawings are erased to the accompaniment of musical instruments like Ilathalom, Kuzhal, Kombu and Chenda.