Tiale O'Brien (4) was all smiles as she explained how they made their t-shirts so colourful.
"We put rubber bands on them and put dye on them, then we waited for them to dry. It took a long time, but when we looked at them they were really pretty and bright."
Tiale says she and her friends wore their yellow t-shirts and brought in a gold coin on Friday, "for people who are sick".
She says the money they raised will go towards helping buy medicine for people who are sick in hospital, but thinks the t-shirts will do something else as well.
"I think they will make people smile when they see them, and that will make them happy."