The fact the Royal Canberra Show is on the same weekend may have put off some families looking to pay $150 to $200 to participate in the Color Run.

Those who have already paid are being offered a refund.

The event was to have been held on Sunday, starting at Stage 88 in Commonwealth Park.

Color Run managing director Graeme Hannan said only 1606 people had signed up for the Canberra run, meaning the event would "not even be close to breaking even".

Mr Hannan gave no guarantees the Canberra Color Run would return, but if it did, it was likely to be held only once every two or three years rather than annually.

It was only the second cancellation in 80 events; the other was the Brisbane Color Run in 2015.

"We are not saying we will never ever come back to Canberra but we need to do some testing and evaluate," Mr Hannan said.

"It's fairly obvious to us the market down there can't substantiate an annual event."

Those who had signed up already received an email this week from the organisers telling them "with a heavy heart" that event had been cancelled.

Mr Hannan said it was not an easy decision, saying he was "shocked and staggered" by the poor response.

"There's a trend all around the world with colour events, numbers are dropping off. Like any brand, it doesn't survive at the peak forever," he said.

"We've seen that in Australia probably a bit more in some cities than others, where the numbers have declined quicker. Smaller markets like Canberra ... where the population base is not so large, the drop-off probably tends to be a bit quicker... The majority of people do it once and because of the smaller population, you're fast running out of people who want to sign up."

The organisers have offered the participants a full refund of their registration fee.

Or they can choose an "at-home colour kit" including T-shirt, sweat band and eight packets of colour.

Billed as "the happiest 5k on the planet", the run saw participants doused in coloured powder and covered in foam in a joyous alternative to the usual fun run. (Its American origins explain the spelling of "color".)

The Color Run debuted in Canberra in 2014, attracting more than 10.000 runners. There were 7000 runners in 2016 and organisers capped numbers at 6000 last year, with 4500 attending.

Organisers said they capped the numbers last year to make the event less crowded and a more pleasurable experience. The move was also an attempt to extend the event's "longevity".

Some potential runners commented on social media on Wednesday that the event was too expensive.

Tickets for a family of two adults and two children would have cost $147 for early-birds or $207 for later inclusion.

Mr Hannan said ticket prices had not risen significantly in recent years. A single ticket started at $38. He conceded the Canberra show and "current economic climate" might have deterred some families from the run.

Mr Hannan said the Starlight Children's Foundation was the run's chosen charity this year, funds raised indirectly rather than the charity receiving a portion of revenue raised by the run.

"Our arrangement with our charities is very much like that of all major fun runs in that the charity has the ability to raise funds via the event by having people donate to them. We do have a relationship with a fundraising organisation which participants can use to donate to their chosen charity. For Starlight we also offer a fee for every volunteer that they provide" he said.
"I want to be clear, as detailed in our website, that TCR is a for-profit company and that whilst we do provide a vehicle for charities to use to raise funds we do not provide any percentage of revenue to any of our charity partners.

"Having said this, we are proud of the charity funds that have been raised via our events over the past six years around Australia. This runs to hundreds of thousands of dollars. "

Following the announcement about Canberra the organisers had responses from people saying they were going to sign up later this week. But they needed to have a critical mass by now to proceed.

"In the last two weeks we were expecting a pick up in Canberra, probably another 1500, which wasn't unreasonable given its history, but it was going nowhere," Mr Hannan said.

"We were doing maybe 20 [registrations] a day when we should have been doing 200 a day."

They did not expect to make any further cancellations of events elsewhere in the country.