In a 2009 study of over 3000 participants, researchers found an average 6 minute difference between how long blondes and brunettes take to get ready. On average, blondes spent 72 minutes per day on their beauty routine, compared to 66 minutes for brunettes. Other interesting facts about this topic:
Natural blondes have an average of 120 - 147k hairs, while brunettes have 100k to 120k
Despite the saying that gentlemen prefer blonds, a study found that men prefer women of their same hair color. Although another big factor is also their life experience growing up
However, blond servers get better tips at restaurants.
On the other hand, however, brunettes are perceived to be more intelligent on first meeting.