Blog competition Day 3

Hi, Rosie here again.

Yes, I worked out what the cure is. It's purple and eaten with salad. Once I worked it out, I had to get everyone to find a way to eat it so they could get better. The teachers were quick to realise I knew the cure and I had to confirm it to them and what I intended doing.
Then, I found out who my mystery emailer was, and they had been testing me all along. But why?
First I had to get everyone better and announced to the school the cure and how I was to help them.
The end of the week I found out that it was going to be Monday when I'd be told the truth about why I was being tested. But then Mr Potter, my arts teacher, gave an idea for a last push to my campaign.
It was whilst chatting to my sister about what had been happening that I came to the conlusion about my school. Was I right?
Weekend came and I relaxed, shopping with my team and awarding them prizes. Then I had a scary thought - were my mum and dad involved in the plot to test me? So I had to keep secret what I suspected.
Finally it was Monday and the tests to really test my powers, but I managed to overcome them and beat them all. The end of the day I was congratulated by everyone and found out the truth. You'll have to read the book to find out what that is.
So, after reading that, here's my question: What colour is the cure?

Leave your answer in the comment and Julie will announce all winners shortly and ask for your snail mail addresses. Thanks for listening to me tell my story.