premise: A clown will select a costume consisting of two pieces and no others: a jacket and overalls. One piece of the costume will be entirely one color, and the other piece will be plaid. Selection is subject to the following restrictions: If the jacket is plaid, then there must be exactly three colors in it. If the overalls are plaid, then there must be exactly two colors in them. The jacket and overalls must have exactly one color in common. Green, red, and violet are the only colors that can be in the jacket. Red, violet, and yellow are the only colors that can be in the overalls. Which one of the following must be false?
hypothesis: Both green and yellow are colors used in the costume.