– he was about 12, slim build with 9…………… hair

Blond(e)

Thông tin trong bài: And can you remember anything else about his appearance?

                Not much. He was quite thin ...

                Colour of hair?

                I do remember that - he was blond. All the others were dark - haired.

=> Màu tóc của cậu bé đó là màu vàng “blond”, còn “dark” cũng chỉ về màu tóc nhưng chỉ miêu tả những đứa trẻ khác.