115.391.  Sample ballots, when and how distributed. — Not later than the fourth Tuesday prior to the primary election, each election authority shall prepare sample official ballots.  The sample ballots shall contain, under the appropriate offices and party designations, the names of all candidates to be voted on in its jurisdiction in the order they will appear on the ballot.  Each sample ballot shall be printed upon tinted or colored paper, of a different tint or color from the official primary ballot, and shall contain no endorsements.  Immediately after having the sample ballots prepared, each election authority shall mail to the chairman of each county committee in its jurisdiction and to each candidate named on the ballot, a copy of the sample ballot for his party.  The election authority shall also post a copy of each sample ballot in a conspicuous place in its office.