In a striking show of support for World AIDS Day, Apple in Australia has again changed the colour of its logo to red at the flagship Sydney store.

The tinted iconic logo illuminated a rainy George Street late on Sunday evening, as onlookers watched on, curious as to what was happening.

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It is the first store in the world to light up in a show of commitment to the (RED) AIDS initiative, that is fighting for an AIDS-free future. Apple will then change the colour of its logo across key stores in Japan, Hong Kong, China, Europe and the United States, as the various timezones tick into Monday.

The 24-hour campaign, which raises awareness for the AIDS pandemic across the world, has been an initiative run by Apple in collaboration with (RED) since 2012.

Apple announced on Nov. 26 that the campaign also includes the ability to purchase 24 apps with exclusive (RED) content until Dec. 7; all proceeds go directly to The Global Fund to fight AIDS. In addition, Apple has committed to donating a percentage of sales at its retail and online stores worldwide on one of the company's biggest shopping days of the year — Cyber Monday on Dec. 1 — which coincides with World AIDS Day.

Proud to announce our largest-ever World AIDS Day campaign. Join us in the fight and help save lives. http://t.co/QzjaL8hExI #AppsforRED — Tim Cook (@tim_cook) November 24, 2014

Another portion of the (RED) Apple initiative was unveiled in the U.S. Apple Store on Black Friday. The company offered different value gift cards included with the purchase of products for 24 hours; a percentage of this amount will be donated by Apple to The Global Fund.

“Apple is a proud supporter of (RED) because we believe the gift of life is the most important gift anyone can give,” company CEO Tim Cook said in a statement. “For eight years, our customers have been helping fight AIDS in Africa by funding life-saving treatments, which are having a profoundly positive impact."

"This year, we are launching our biggest fundraising push yet with the participation of Apple’s retail and online stores, and some of the brightest minds in the App Store are lending their talents to the effort, as well.”

The red Apple logo being installed in Sydney. Image: Jenni Ryall / Mashable

So farm Apple has donated $75 million USD to the (RED) campaign, which was started by Bono and Bobby Shriver in 2006. AIDS has killed 39 million people, and 35 million people in the world currently live with HIV. The (RED) campaign is trying to create an AIDS-free future by getting businesses, including Apple, Nike, American Express, Coca-Cola and Starbucks, to help fund access to life-saving medication.