W. Va. Code § 3-5-12
There shall be a separate ballot printed on different colored paper for each political party participating in the primary election and the ballot of no two parties may be of the same color or tint. The Secretary of State shall select and determine the color of the paper of the ballot of each of the parties, and shall notify the clerk of the county commission of each county thereof, at the time he or she certifies the names of the candidates of the various parties to the clerk, as herein provided.
A different color of paper shall be selected and designated by the Secretary of State for each party. The sample ballots of each party shall be of a different color than the official ballot and of a different color from one another. There shall be printed across the face of such sample ballot in large letters the words "sample ballot". No sample ballot shall be voted or counted in any election.
W. Va. Code § 3-5-12