You may be wondering "but Joe, how does this relate to rainbows?" Well, what do you find at the end of rainbows? A pot of gold and a leprechaun that won't let you take the gold. Leprechauns are generally small and stingy that keep to the darkness and hoard gold. I decided to create my vision of a leprechaun's pot of gold, as a TARDIS interior. There is still a rainbow aspect in this interior, and it's coming in the side of the old pot as it has a hole in it's lid.
Such a cool concept!