That is the current standard for an RJ61X jack, which is not the case here. Still, there's no reason that it cannot be used. It makes no sense to wire anything to positions 2,3,6 and 7 since they don't do anything in an RJ31X.
In the case of an RJ31X, there is not a defined color standard. The phone line just goes in on one pair and comes out on another. I use the white/blue pair for the line in and the white/orange for the line back out.
