Oliver said it was essential to show support for those worthwhile charities.
"You never know when you might need that organisation's support so if you can get the word out there like we're trying to do, that's got to be a bonus for everyone."
Taradale Intermediate School teacher Kirsten Demanser-Wilson said students in the school leadership team chose the foundation as their charity to support for mufti day.
"This was their voice and this was what they wanted to support," she said.
"It's great to see the kids showing empathy for others and thinking about other people that aren't as lucky that have got those medical conditions that they're fighting."
Havelock North Intermediate was another school that took part and mum Helen Lawson said she was happy to see the school supporting her 12-year-old son who was diagnosed with acute lymphoblastic leukaemia in 2015.
"It's great to see people get in behind it," she said.
"Not much was ever said about kids having cancer. Unfortunately it is very prevalent and just to have that awareness out there is good."
Lawson, who was diagnosed herself with breast cancer in 2012, said the foundation offered valuable group activities for the children.
"It's just child cancer patients so no one is looking at anyone weirdly, nobody will come along if they're ill.
"It gives them a slice of normality but in a controlled way."