Participants were showered with coloured powder as they ran the 5km course. Click for more photos

The Swisse Color Run

Participants were showered with coloured powder as they ran the 5km course. Photo: Marco Del Grande

It starts with yellow, then orange, then blue, then pink, and ends five kilometres later with tens of thousands of multi-coloured people.

About 20,000 families, couples and friends have taken part in Sydney’s first ever Color Run (spelled the US way) - a fun run that leaves its participants covered in coloured powder.

The run, which kicked off on Sunday morning at Sydney Olympic Park, includes four stages where runners are pelted with a different colour.

Runners start the day dressed in all white and finish the run looking more like a rainbow.

"It was really, really magical," a Color Run spokeswoman said of the first ever event in Sydney.

"We call it the happiest  five kilometres on the planet and it’s hard to argue with that when you’re here."

In November, Melbourne became the first city in Australia to host the event.

The sold-out Sydney Color Run raised about $200,000 for Heartkids and will now tour around the country.

The powder used is food grade corn starch with added food colouring.

The MS Colour Run (spelled the Australian English way) was held on Australia Day.

AAP, smh.com.au