On the Subject of Juxtacolour Flash

Dictum Quatanium: “Whether you are black, white, yellow, or purple, we should all help the guy who is purple. He’s choking!”

  • A Juxtacolour Flash module displays a sequence of words in different colours with no breaks between repeats.
  • The sequence is generated by two scanners moving in alternating directions along rails of 5 cells in length somewhere in the 11×11 grid below. Initially, one moves horizontally and the other vertically.
  • One of the scanners translates the colours of the cells into words and the other generates the colours of the words.
  • Press the buttons to move the rails from their initial positions to their corresponding targets without making any invalid moves.

Initial and Target positions

  • The initial position of a rail is at its centre, at least 2 spaces away from any edge of the grid.
  • The target position of the word rail is the position of the first character of the serial number.
  • The target position of the colour rail is the position of the second character of the serial number.


  • Pressing the buttons recalibrates the scanners by moving the centres of their rails to the scanners' locations and rotating them 90°.
  • Pressing the Yes button recalibrates the rail of the word scanner and pressing the No button recalibrates the rail of the colour scanner.
  • Rails cannot go off of the edge of the grid. Instead the rail is centred at the cell that is 2 spaces away from the edge. The position of the rail is unchanged, and thus does not align with its centre.
  • No recalibrations are performed if the movement is invalid.

Invalid Moves

  • There is a wall between the scanner and the position of the rail.
    To find where the walls lie:
    1. Take the configuration of walls corresponding to the range of letters the last letter of the serial number falls into.
    2. Take the sum of the numbers in the serial number modulo 6 and apply its corresponding transformation.
  • The move would result in the two rails intersecting one another.
    • This does not apply if the intersection point is one of the rails' target positions.
    • If the module was in a position were intersecting rails are unavoidable, the module will reset the rails to their initial positions, keeping their current orientations.

The module is solved once both rails are positioned at their respective targets, regardless of whether or not the rails intersect after the last move.

190° Clockwise Rotation
290° Anticlockwise Rotation
3Vertical Flip
4Horizontal Flip
5180° Rotation