My sister at not quite 60 has snow white hair. (It is gorgeous) I am 4 years older, but mine is still mostly brown. Genetics play a role.
I doubt if Trump dyed his hair. It looks good.
The guys in my family start going bald before 30.
The females don’t lose their hair. We just start going gray. I started going gray in my early twenties.
I don’t dye mine, so it’s been graying for decades.
Anyone who judges cognitive ability based on hair color is foolish.