A court decision in a single country does not change the world. Yet the US Supreme Court's ruling on same-sex marriage has sparked a colour revolution across the globe. Soon after the top judges ruled that marriage was a right for all US citizens, social media sites were awash with rainbow colours - a symbol for gay pride. Colourful parades were also staged in other countries last weekend, celebrating what is seen as a victory for sexual minorities. That the landmark ruling has resonated around the world is unsurprising. Marriage, the ruling says, cannot stand in isolation from developments in law and society. US President Barack Obama said the decision affirmed what many had already embraced.

Whether it will prompt more countries to legalise same-sex marriage remains to be seen. But groups campaigning for and against it have become more vocal in the wake of the decision. Last Saturday, the Equal Opportunities Commission chairman, York Chow Yat-ngok, joined the chorus calling for more discussion on the subject in Hong Kong, adding that the government should take the lead. Chow is right in saying that Hong Kong needs to tackle the issue. The US ruling is expected to renew pressure on our government. But if previous experience is any guide, the campaign won't be easy. The watchdog was criticised by conservative groups for promoting homosexual relationships when it sought to extend the protection under the existing anti-discrimination laws for same-sex couples. The rush to display the rainbow colours on social media has already sparked a war of words similar to that during the Occupy protests last year. Some commentaries even warned that there might be fake gay and lesbian marriages to take advantage of public housing and welfare benefits.

The prejudice against sexual minorities is a result of misunderstandings and long-held values and beliefs. While there is a strong case for the need to introduce legislative protection for the vulnerable, it also shows that we have to tackle the issue with care and sensitivity.