* Blonde hair contains a pigment called pheomelanin. This pigment absorbs less light than the eumelanin found in darker hair colors. This means that blonde hair reflects more light, giving it a lighter appearance.
* Yellow hair, on the other hand, is usually a result of bleached or damaged hair. The bleaching process removes the natural melanin pigments, leaving the hair with a pale, yellowish hue. This yellow color is often due to the breakdown of the hair's structure, which leads to a change in its light reflection properties.
In essence:
* Blonde hair has a specific type of pigment (pheomelanin) that gives it its characteristic light color.
* Yellow hair is often a result of damage or chemical treatment, where the natural pigments are removed.
It's important to note that the distinction between blonde and yellow can be subjective. Some people might consider very light blonde hair to be yellow, while others might describe yellow hair as a result of bleaching or sun damage.