Several options come to mind:
Bright hippy colors in a flower scheme (ala Rowan & Martin's Laugh-In);
Metalic Silver with UFO/Area51/little green men/ and "UFO Ground Support" on the doors...
(Oh, you wanted to blend in, didn't you?)
How about grass on the bottom, cityscape across torso high, and sky on top---> Urban Camo?
Paisley?
Ok... enuff!!!
ON a more realistic note:
Centeral High School (here in San Angelo, TX) has the exterior of their Art Department building as a LARGE canvas for the students to paint each year. Each student has a panel on the wall about 16'x16' or more.... all are very creative. How about contacting your local schools - propose an artistic paint scheme contest... The winner's concept to be painted on your "canvas". The bigger benefit is that if you supply the paint, they can supply the LABOR!!!! (Just a thought)
Let us know what you decide and how it turns out.... We'll be WATCHING
....