What white clothing signals
Walk into almost any major Sri Lankan Buddhist temple on a full moon day and the crowd is overwhelmingly dressed in white. The practice is widespread among Sinhalese Buddhist laypeople, who wear white or very light, plain clothing when they go to a temple to observe the precepts, listen to a sermon or make offerings. The colour is generally understood as a sign of purity and simplicity, and of setting aside ordinary display for the day. Some people explain it simply as the clothing appropriate for devotion.
It is a custom rather than a strict rule, and it varies. Many people wear white only on full moon days or on special occasions. On an ordinary day a visitor may see worshippers in everyday clothes that are modest and clean. Nobody expects a foreign visitor to own white clothes, although light-coloured, loose garments are a sensible choice and are often appreciated.
Dress for visitors
The general principle is to cover the shoulders and the knees, and to avoid anything tight, transparent or revealing. Sleeveless tops, short skirts and shorts are widely considered inappropriate at shrines. Hats and caps are normally removed, and shoes and socks are left outside, often at a designated place. Pavements and stones can be extremely hot at midday, so many people carry thin socks for walking between shrines where footwear is not allowed, though some temples do not permit even socks within certain areas, so follow local guidance. A temple dress code like this is common across Buddhist countries, though the details differ.
Visitors have occasionally been refused entry or asked to leave for clothing that was judged disrespectful, and for images or tattoos of the Buddha displayed on the body. Rules are enforced more strictly at the best-known sites, but the underlying idea is the same everywhere.
Flower offerings
Offering flowers is one of the most common acts of devotion. Near the entrance to a major temple there are usually stalls selling small trays or bundles of blossoms, often lotus buds, jasmine and the white or cream flowers of the frangipani, known locally as araliya. Worshippers place them on an altar table in front of the image or at the base of a stupa or Bodhi tree.
The practice is often explained through the idea of impermanence: the flowers are beautiful, they fade quickly, and so they remind the giver that all things change. There is also the general merit of generosity and the wish to honour the Buddha. Many people carry the flowers with both hands and avoid smelling them first, since they are meant for the offering. Different families and teachers explain the details differently, so follow what you see locally. The lotus has a long history in Buddhist art, discussed under lotus symbolism, which is part of why it is so often chosen.
Oil lamps and incense
Lighting a lamp is another typical act. Traditional lamps burn coconut oil or other vegetable oil, and many temples have a tiered stand or a stone lamp holder where worshippers light a wick. Lamps are generally understood to stand for the light of the Buddha’s teaching dispelling ignorance. Incense, where used, is offered in a similar spirit. Modern sites sometimes substitute electric lights or provide candles, depending on the building and on fire concerns.
Water is also offered. At a Bodhi tree, devotees often pour water at the base or at the surrounding terrace as a gesture of respect and care. These are the sorts of shrine offerings that visitors will see in many Buddhist countries, expressed in Sri Lankan forms.
Gestures of respect
Worshippers typically greet an image or a stupa with joined hands raised to the forehead and a bow or a kneeling prostration, sometimes with a short chant. Visitors do not need to copy this, but should avoid standing in front of people who are praying and should not walk in front of a person making an offering. Do not turn your back on a Buddha image to take a selfie, and avoid pointing your feet toward images or monks. Ask before photographing worshippers and avoid flash in shrine rooms.
Women should not touch monks or hand things directly to them; in many settings an offering to a monk is placed on a cloth or table. This is part of the wider courtesy toward monastics seen in Buddhist countries.
Regional and temple variation
Sri Lanka is not uniform. Temples in the up-country Kandyan region, in the southern low country and in the northern and eastern areas can differ in architecture, style of offerings and the balance between Buddhist and Hindu practice. Many Buddhist temples have a separate shrine to a deity such as Vishnu, Saman or Kataragama, where flowers and offerings are made in slightly different ways, and some Hindu kovils are also visited by Buddhists. The Tamil Hindu temples of the north follow their own customs, and Sri Lankan Muslims and Christians have distinct practices too.
Because of this, the safest approach is observation. Watch what locals do, ask quietly if unsure, and follow any signs. Customs also change over time and between generations, and dress rules at particular sites can be tightened or relaxed, so check current guidance from the temple or from official sources before a visit.