Somebody here did attempt to plot hair colour using a dating site but I the results are very flawed for numerous reasons. Most blondes get their hair colour from a bottle.
http://www.forumbiodiversity.com/showthread.php/34124-Hair-Colour-in-England
Many children born with blond hair develop darker hair as they age, with the majority of natural blonds developing a hair color of a dark "gunmetal" hue by the time they reach middle age. Pregnancy hormones hasten this process. Natural blond hair is rare in adulthood, with some reports stating that only about 2% of the world's population is naturally blond.[3] Blond hair is most commonly found in Northern and Eastern Europeans and their descendants but can be found spread around most of Europe. Blond hair is rare outside of Europe but can also be found in populations in South America and Australia. Studies in 2012 showed that naturally blond hair of Melanesians is caused by a recessive mutation in tyrosinase-related protein 1 (TYRP1). In the Solomon Islands, 26% of the population carry the gene; however, it is absent outside of Oceania.
We do have far more redheads, mostly in Scotland, but throughout the UK as well.
Red hair ranges from light strawberry blond shades to titian, copper and less commonly "true" red. ... At 1-2% of the population, it is the least common hair color in the world. It is most prominently found in Scotland, Ireland and England. Scotland has the highest proportion of redheads; 13 percent of the population has red hair and approximately 40 percent carries the recessive redhead gene.
http://en.wikipedia.org/wiki/Human_hair_color#Blond_hair