The ceremony was on the grounds of the exclusive Bangalore Club, an oasis in one of India’s largest cities. The bride-to-be, Sreya Muthukumar, was ensconced on the terrace, wreathed in smiles, greeting and chatting with her guests. Two women were attending to her, each wielding a thin plastic cone filled with henna paste.

For seven hours last Thursday, the artists drew freehand, etching patterns, motifs and mandalas on Ms. Muthukumar’s limbs. When they were done, dark green lines stretched from the tips of her fingers to above her elbows. Four other artists catered to the palms of guests. Once the henna paste, known as mehndi, dried, it was washed or scraped off to reveal the bright orange stain that has long been associated with Indian weddings — no matter how modest or lavish.

“After all those hours, when, in the end, the bride looks at her hands and says ‘I love it,’ that’s the high point for me,” said Sunitha Parihar, who adorned Ms. Muthukumar’s arms. “We mehndi artists are so important to make the bride look and feel beautiful on her big day.”

Big wedding celebrations are the norm in India for those who can afford it, and have led to a cottage industry of henna artists. But the ritual is also a reminder of the vast disparity that persists in India, where the number of billionaires has tripled over a decade while 90 percent of the country makes less than $3,900 a year.

Ms. Muthukumar’s nuptials were far from the season’s most lavish — that distinction goes to the union of Anant Ambani and Radhika Merchant, whose wedding festivities this weekend are the culmination of a monthslong extravaganza that has put a global spotlight on India’s new Gilded Age.