Stunning images taken by Sean Lenz, 19, and Kristoffer Abligaard, 20, show picturesque waterfalls transformed into vibrant rainbows of colour. The awe-inspiring images were created by clever use of long exposure photography and glow sticks floating through water. Photo: Picturesque waterfalls transformed into rainbows of colour. (Photo by Sean Lenz/Kristoffer Abildgaard)

An Indian Hindu devotee celebrates Holi, the spring festival of colours, during a traditional gathering at a temple in Nandgaon village in Uttar Pradesh state on March 16, 2019. Holi, the popular Hindu spring festival of colours is observed in India at the end of the winter season on the last full moon of the lunar month. (Photo by Noemi Cassanelli/AFP Photo)

Revellers celebrate "Ash Monday" by participating in a colourful "flour war", a traditional festivity marking the end of the carnival season and the start of the 40-day Lent period until the Orthodox Easter,in the port town of Galaxidi, some 215 km (134 miles) north west of Athens, March 18, 2013. The revellers "fight" by throwing coloured flour, charcoal dust and powder painting until they essentially run out of supplies. (Photo by Yannis Behrakis/Reuters)

Hindu devotees play with coloured powders during Holi celebrations at the Bankey Bihari Temple on March 21, 2011 in Vrindavan, India. Holi, the spring festival of colours, is celebrated by Hindus around the world in an explosion of colour to mark the end of the winter. (Photo by Majid Saeedi/Getty Images)

A mahout guards the elephants during the annual Vrischikolsavam festival, which features a colourful procession of decorated elephants along with drum concerts, at a temple in Kochi, India, November 18, 2017. (Photo by Sivaram V/Reuters)

A man daubed in colours looks on as he takes part in “Lathmar Holi” celebrations inside a temple in the town of Barsana, in Uttar Pradesh, India, March 15, 2019. (Photo by Altaf Hussain/Reuters)

A girl covers her face as she is daubed in colours during the religious festival of Holi inside a temple in Nandgaon village, in the state of Uttar Pradesh, India, March 5, 2020. (Photo by Adnan Abidi/Reuters)