This is the 10952nd most frequent Korean word.
금발이다
To be blonde.
The word '금발이다' describes the characteristic of having blonde hair, used literally to denote someone's hair color.
그녀는 금발이다.
She has blonde hair.
Here, '금발이다' relates to the wished appearance in the dream, slightly figurative in its aspirational sense.
그의 꿈은 금발이다.
His dream is to have blonde hair.
In this context, '금발이다' is used descriptively to explain a phenomenon or result of exposure, leaning towards an abstract explanation.