According Jim Moini on his Crazy License Plate page, the colors of the stickers are each fairly accurate to the actual colors used on the state license plates in 1976.
Nine in the series are Snow White-themed.
A fold-out poster of the United States was available with spaces for all 50 stickers to be applied. It also had games and puzzles on it for kids to enjoy. Open dimensions: 22.5" x 25.5". No copyright date is included.
Special thanks to Steve Garner of the Disney License Plate Catalog for sharing the images of the individual Snow White sticker sheets as well as the give-away poster.
Here's the complete set...
Complete set images via Bubble Gum Cards.