Why does the Order of the phonex book describe Tonks' hair as bubblegum màu hồng, hồng and in the movie it's purple

They must have thought purple looked better. Maybe they tried a form of màu hồng, hồng and didn't like it. Did she have màu hồng, hồng hair at all in any of the films?

I think the same. But I've always thougth that it looks better this way