WATCHING Hi-5 rehearse at Singapore Expo is like seeing the colours of the rainbow coming to life, singing and dancing.

This is the sixth time the group has come to Singapore to perform, and the members' beaming smiles are as wide as ever and their costumes just as outlandish.

What has changed is that original Hi-5 members Kathleen de Leon and Tim Harding, both 29, are not here.

Sun Park, 26, who was here last year as the temporary replacement for de Leon when she went on hiatus for go give birth last year, is now a permanent fixture.

de Leon, who is married to former Savage Garden member Daniel Jones, quit the group to be a full-time mum after giving birth last July.

As for Harding, he had a motorcycle accident a few months ago and injured his foot. While he can walk, he will be unable to dance for an as yet indeterminate amount of time.

Hi-5 understudy Steven Nicholson, 23, will temporarily take his place.

The two will be dancing alongside stalwarts Nathan Foley, 27, Kellie Hoggart, 33 and Charli Robinson, 27.

Despite this line-up juggle, Hi-5, who are nothing if not relentlessly positive, insists that the chemistry has not changed.

Said Hoggart: 'It brings new energy to the show and it'll be good for the Singapore audience to come along and see a fresh new energy - it only made the show bigger and better.'

The others said the newcomer, Steve, was like a 'little brother' to them.

Nicholson, who was trained in dancing and singing, said the others were very welcoming.

What astonished him most was how similar in real life the members of Hi-5 were to their effervescent onscreen personas.

'I was surprised how much Charli was actually Charli, Kellie was actually Kellie... the strength of the group was that everyone was playing themselves,' he said.

But how have the fans, especially the kids, taken to the changes?

Nicholson said: 'They're accepting of the change. They'll adapt to that - and they are more than happy to ride the rollercoaster with you.'

Robinson added: 'I remember last time in Singapore... They were screaming out to Sun. They were going, 'Sun, Sun!' I was thinking, well, that took 30 seconds!'

Personnel changes aren't the only differences this year.

This is also the world premier of Hi-5 Circus - a carnival-themed live stage show. It includes juggling, acrobatic feats, and even swinging on a flying trapeze.

For Hi-5, this is its most demanding show yet. But there is also a sense of excitement that it could also be their best.

In fact, after a preview show in Sydney a few months ago, the group decided to enroll themselves in 'circus school' for a week.

There were no accidents on set and the only injuries they received were bruises.

Each trapeze act takes only a few minutes.

Said Foley with his typical droll humour: 'Once your ears start bleeding, you have got to stop.'

Said Nicholson: 'It's one thing to hang upside down on a trapeze but to be singing as well? That's something you don't see in any other circus.'