Luscious greens, egg-yolk yellows and delicate oranges flickered across waterways in the Thai capital Bangkok, as virtual projections of the Loy Krathong festival's traditional offerings reduced waste at the popular event.
The annual festival, celebrated on Monday, sees millions ask forgiveness from the river goddess Khongkha by releasing colourful floats into waters across Thailand under a full moon.
In recent years environmentalists have expressed concern as Bangkok's already clogged waterways are increasingly choked by the plastic and foliage "krathongs", as the offerings are known.
To combat this, a Bangkok Metropolitan Administration (BMA) initiative took a fresh approach to the centuries-old tradition.
Rather than floating the elaborately constructed offerings -- which include leaves, flowers, plastic, candles, incense sticks and sometimes coins -- people were asked to create digital krathong.
After colouring-in drawings of krathong on paper, or on their phones, attendees' sketches were scanned and then projected onto the city's Ong Ang Canal.
"The tradition still remains. But we must integrate the festival to be up-to-date, in order to create less impact and less pollution on nature," attendee Chainarong Tumapha, 27, told AFP.
After colouring-in her krathong, Phattarika Kiltontiwanich agreed change was needed.
"I'm quite concerned since the environmental issues have grown much bigger," the 23-year-old told AFP.
The BMA said about 3,700 images were projected across the nighttime waters.
"We can see that it's getting a lot of attention, especially among young people," Bangkok official Pornphrom Vikitsreth told AFP.
But the numbers were dwarfed by Bangkokians choosing to release the more traditional floats, with officials saying that more 600,000 were removed from the city's waters.
The BMA said polystyrene usage was down three percent from last year, with the vast majority of offerings made from natural materials.
As people cast off their floats, tugs and small vessels bobbed in the Chao Phraya River, with workers scooping krathongs from the choppy waters.
The collected material will be sorted, with biodegradable elements turned into compost and plastic sent to landfill.
Near the Icon Siam luxury mall, where the krathongs were guided into the Chao Phraya by golden-painted slides, revellers enjoyed a more traditional celebration.
"If we don't continue [Loy Krathong], our children and grandchildren will not see this," said 57-year-old Tanaporn Karueksom.