Well the payoff corresponding to each action profile is a 2-vector of reals, saying that they are all distinct doesn't mean that they cannot still have one component equal, wherein lies the problem.
(2,1)|(1,1)
-----------
(2,2)|(1,2)
for instance has all action profiles as pure strat Nash equilibria. If you meant (as I am guessing you did) that every element of every payoff vector is distinct, then the key idea is that we cannot have two Nash equilibria in any row or column (as one would be preferred by the player whose action set give rise to the row or column).
And your colourings correspond to permutations of the set {1,2,...,n}, of which there are exactly n!.
The each colouring is equivalent to placing n rooks on an nxn chessboard in such a way that no two are attacking each other. From this observation iii) is clear.