* Region/Country: Hair color trends vary widely around the world.
* Age Group: Younger people might favor different colors than older adults.
* Time Period: Trends change! What's popular now might not be in a year or two.
* Natural vs. Dyed: Are we talking about the most common *natural* hair color, or the most frequently *chosen* hair color in salons?
However, generally speaking:
* Worldwide (natural): Black/Dark Brown is the most common natural hair color globally. This is largely due to population distribution.
* In salons (dyed): Brown/Brunette shades are usually the most requested and popular. It's versatile, flattering to many skin tones, and often seen as a "safe" or classic choice. However, blonde shades are also very popular, and the trend of balayage/highlights/ombré are constantly evolving.
* Recently: The trend of natural shades and low-maintenance colors has increased.
* Other colors: Colors like red, copper, gray/silver, and fashion colors (pink, blue, purple, etc.) are popular in specific subcultures or as trends but don't have the overall popularity of brown or blonde.
To summarize:
If you're asking about *natural* hair color, black/dark brown is the most prevalent worldwide. If you're asking about the most popular *salon* color, brown/brunette is a safe bet, closely followed by variations of blonde.
Ultimately, "most popular" is always a moving target!