Students in more than 90 Australian high schools will wear purple later this month to underline that everybody – whatever their sex, sexuality or gender identity – has the right to feel proud of who they are.

Wear It Purple is a student-driven campaign which began in 2010 as a collaboration between a high school and a university student in response to soaring youth suicide numbers linked to bullying based on sexuality and gender identity . LBGTI students are six times more likely to contemplate suicide than their straight counterparts.

A 2014 study, Growing Up Queer, by the Young and Well Co-operative Research Centre found that around two-thirds of LGBTI young people reported being bullied because of their sexual orientation and school was by far the most likely environment for it to occur.

Wear It Purple’s Operations Officer, Naomi Graham, said the day had evolved into a day of acceptance and celebration of all rainbow young people. She said that a growing number of schools were registering every year, with registrations still open for the August 28 day.

“Schools, workplaces, tertiary and community organisations wear purple to raise awareness and it shows rainbow young people that they are accepted, they’re not alone and they have a right to be proud of who they are,” Ms Graham said.

“There’s always going to be work to do but we’re seeing a really positive shift in the student body and also staff. Obviously, there is always support from places such as Newtown [inner-west Sydney] but when we see more religious schools and private schools getting on board it’s a really positive shift.”

Bodies like the NSW Teachers Federation had done a lot of work to talk to teachers about homophobia and transphobia and what was and wasn’t acceptable in classrooms.

But there is still work to do. Many of the schools involved are in NSW or Victoria and Wear It Purple is keen to reach out to other states and territories, particularly in rural and remote areas.

Although schools in some areas may not be part of the event, Wear It Purple is running ‘hubs’ in community buildings with the help of several organisations.

The theme of this year’s Wear It Purple Day is “Colour Your Perception” and this deals with the assumptions that people make about one another, for example, that a child has a mother and father or that a person is straight.

Schools also have the option to advance screen “Gayby Baby”, a documentary that follows four children in different same-sex families, before it goes on general release.

While the Safe Schools Coalition (SSC), which provides resources and training to schools about LGBTI students, staff and families, has attracted a strident publicity campaign against it from the Australian Christian Lobby, Wear It Purple has mostly escaped such attention in recent times.

Asked why this was, Ms Graham said it was probably because it did not attract government funding and it had a pretty simple, apolitical message that was hard to argue with. SSC is federally government funded at around $8 million.

The NSW Police will run a big event in Hyde Park, with a barbecue and photo booth, and they will also be going into schools. Wear It Purple is sponsored by Telstra and HSBC.