My parents (both blond) had three children - all of us redheads. (Despite my mother’s calumnies against the milkman, we’re pretty sure the red hair came from my father’s mother - Irish - and/or from my German great-grandfather…)
All of my parents’ six grandchildren have one brunette parent and one red-haired parent. There are blonde, 2 brunettes, and 3 redheads in the bunch, and we’ll soon find out which group the new baby falls into. So I guess we’re doing a little bit better than the genetic odds would suggest as far as continuing the breed.
And in the spirit of adding to the observations, my siblings and I all have medium-to-light auburn hair (not carrotty,) and disappearingly blonde eyebrows.
Also, I seem to recall reading about the advantage of fair skin (and presumably the hair pigmentation that comes along with the skin) a while back: Something to do with an advantage in reproduction in far northern climes with limited sunlight, and the ability to produce more Vitamin D? (Which implies a corresponding disadvantage in more equatorial environments.) So, if the research is correct that the gene variation for red hair appeared about 50,000 years ago, it would have been advantageous in northern Europe during the last Ice Age, I presume?