  The Hales-Jewett Theorem states that any $r$-colouring of $[m]^n$ contains a
monochromatic combinatorial line if $n$ is large enough. Shelah's proof of the
theorem implies that for $m = 3$ there always exists a monochromatic
combinatorial lines whose set of active coordinates is the union of at most $r$
intervals. Conlon and Kam\v{c}ev proved the existence of colourings for which
it cannot be fewer than $r$ intervals if $r$ is odd. For $r = 2$ however,
Leader and R\"aty showed that one can always find a monochromatic combinatorial
line whose active coordinate set is a single interval. In this paper, we extend
the result of Leader and R\"aty to the case of all even $r$, showing that one
can always find a monochromatic combinatorial line in $[3]^n$ whose set of
active coordinate is the union of at most $r-1$ intervals.
