He looked really good with his hair going gray in the last years of Bonanza.
It's funny I HATED it LOL
He started going gray pretty young and had to color it all the time. I guess he got tired of it. Looks more like Pa Ingalls in the later eps.
Not a fan of the salt and pe0er hair
I notice in the lost episodes it varies greatly week to week. In one episode out in the sun he looked all grey and then the following week he had only a touch of grey.