>>213743111The map is horse shit anyway. You can literally see the outline of the South/Lower Midwest (where Southerners settled) vs Upper Midwest. Someone just googled "british ancestry in the U.S" and "German ancestry in the U.S" then made the map.
I doubt there's any true statistics on hair color %. The only way to do it I can think of is doing it with new born babies, but half of them are bald and the few that aren't their hair usually darkens as they age.