Rangoli is a form of Indian folk art that uses colored rice, sand, flour or flower petals to make intricate, geometric designs. It is often done around Diwali, or the Hindu "festival of lights," which was just celebrated on November 11th and 12th of this year. Diwali symbolizes light's victory over darkness, and people decorate their houses and temples with bright, colorful lights to reflect this.
It's no wonder this art form is so popular during Diwali. The colorful materials and unique designs must look brilliant when they meet the lights shining from a neighbor's home.