I have a vague memory of a book my mum read to me before she passed away when I was very young. I think it was a book for young readers but it was decently thick. I'm from Australia, but I'm not sure if it's an Australian author, I think it might be. The story had to do with a rainbow coat and the theme was hypnosis. Might anyone have read this book or know about it? I'm almost certain I could recognise the book by the cover art, it was read to me maybe 10 years ago when I was around 12.
Maybe someone who read a lot as a teenager in Australia could tell me the name of this book.