Hair color isn’t fixed at one exact age. It often keeps changing through childhood and puberty , and many people don’t see their fully settled natural shade until the teen years.

A simple way to think about it:

  • Babies’ hair can shift a lot in the first few years.
  • Some children’s hair keeps darkening until about 6 or 7.
  • Puberty can also change how much pigment the hair makes, so the “final” color may show up in adolescence.
  • Graying usually starts much later, often in the 30s.

Quick scoop

If you mean when hair color becomes noticeable , that can be very early. If you mean when it stops changing , that is often around childhood to the teen years, though it varies by person.

“Hair color is not set for life.”

Practical takeaway

  • Baby/toddler years: color may shift a lot.
  • Childhood: gradual darkening is common.
  • Teen years: many people reach their most stable natural shade.
  • Adulthood: graying becomes more common later on.

Stage| What can happen
---|---
Birth to 5 years| Hair pigmentation can change noticeably. 1
Around 6–7 years| Some children’s color becomes more stable. 8
Puberty/teen years| Natural shade may become more defined. 7
30s and later| Graying often begins. 29

Bottom line

So, the best answer is: hair color can start changing at birth and often keeps changing until childhood or the teen years , depending on genetics and development.