It's a few blocks from the main railway station but not the most inviting area at night. Official age of consent in Sri Lanka is 16 for girls and 18 for boys. The country also has a reputation for prostitution by young boys. So the underage male prostitution situation isn't pervasive throughout the country as some media reports might lead you to believe. Sri Lankans are generally very friendly and easygoing.
Touts can be a nuisance, though.
Discretion seems to be important for sex-oriented businesses to stay in business, and there's probably some bribery involved in it, too. Costs for transit and accommodation are very low, there's Internet access from a cybercafe in Colombo, and restaurants and casinos in Colombo are good, too. Like Thailand, street crime is very unusual and violent crime especially rare. The civil war in the north and east is well outside most tourist areas. About the most unnerving aspect is all the heavily armed security they've had to post in Colombo to guard against Tamil truck bombs.