Tardis blue, mainly based on the character design, because in the story, Jonas (the main character) is wearing a dark blue jacket, which lets him stand out from the pastel enviroment.
My idea is based on a story that I did for an exam back in high school in 2009, and it's about a boy who ends up in his sister's dream world, which basically consists of pastel colours and faceless mannequins.
I was thinking of a story book design, therefore I'm going to create the interface like a storybook, with the different options and pages as actual pages in the book.
Here's the basic layout design, though very simple and with no colours or pictures so far:
(please ignore what the pages in the book actually says, it's mostly just filler text)