* Sun exposure: Even dark hair can be affected by the sun, leading to lighter streaks at the top layers, especially around the face. This is often referred to as "sun-kissed" hair.
* Genetics: People with darker hair can still have variations in their hair pigment, resulting in naturally lighter strands throughout their hair. These can range from subtle to quite noticeable.
* Age: As we age, our hair pigment can change, sometimes leading to strands that are lighter than the rest.
So, while blonde hair is often associated with highlights, it's important to remember that natural highlights can occur in all hair colors, just in different shades and patterns.