Unfortunately, that cannot be known as there are no dual-typing moves as of yet. My guess is that the first type listed- for instance, say something was Steel/Ice type- would be the one. From my example, if there was a Steel/Ice type move, then Color Change would be Steel.
Either that or it would be random. --- Pokemon SoulSilver FC: 1335 1407 6427 When Life gives you lemons, throw them back and demand cookies instead! -Official Sandslash of the PMD3 boards
I don't think Gamefreak is willing to destroy their series, when all they really have to do is give us new abilities, moves, pokemon, and a new region, and we'll buy it. --- http://i.imgur.com/xWWX5xm.jpg http://i.imgur.com/tMhFpCD.jpg Thanks Fellwolf and L4DHunter! <3