I once briftered up a bike to 8-sp STI, used the same white brake housing on the whole shebang. It worked fairly well. I'd definitely not try it again, because I know better, and as far as 9s and 10s, there are enough issues with adjustment to deal with, no sense in messing it up with housing.

My most recent build is 5-speed, anyway, and it's pretty ambivalent about whatever is used.