Does red go to black on a 3-way switch?

In a standard 3-way light switch wiring configuration using three-conductor cable (14/3 or 12/3), both the black wire and the red wire serve as the two "traveler" conductors running between the two switch boxes. Therefore, connecting the red traveler wire to one brass traveler terminal and the black traveler wire to the other brass traveler terminal on both switches is completely standard and correct. However, neither the red nor the black traveler wire should ever be connected to the dark common terminal unless specifically designated by a professional wiring diagram. You can troubleshoot wiring paths easily. You can verify that your corrective action is successful when matching black and red travelers to the brass traveler screws on both ends ensures proper multi-location circuit continuity.