More than 80% of pupils at the school wore something pink yesterday to support the "Pink Shirt Day" national campaign against bullying.
The campaign empowers young people to reject bullying, celebrate diversity and promote positive social relationships.
"It's to promote positive behaviour and stand up against bullying," Calla Knudson-Hollebon (15) said.
The campaign aimed to create a community where everyone felt safe, valued and respected, OGHS assistant principal Sue Lynch said.
The event started in 2007 in Nova Scotia, Canada, after a school pupil who was bullied for wearing a pink shirt was given a moving show of solidarity when his classmates turned up for school the next day all wearing pink shirts.
"Pink Shirt Day" has been held annually in New Zealand since 2009.
