What is this white powder on my shrub branches?

There is some kind of fungus/powder killing my shrub. It is NOT on the leaves but on the branches and started from the bottom. First the leaves fall off the branch then it seems to just climb higher. It's not that easy to wipe off and when I do, the color is sort of orange-y white. I don't know what kind of shrub it is but the leaves & branches are purple and do fall off in the winter. HELP! I have no idea what to do!!