I did these two colour tests:
The one on the left used brighter colours, and more neutral ones were used on the right. As this is an adult program, I need to find a way of combining the child-like look with something which would be appealing to an older audience. I think one way of doing this would be to bring the colours down to a more neutral look.
I had a go at making it look more mature with some textures and 'grown up' colours: