Question

what is wrong with \ojo negros\?
nothing is wrong with this sentence.
the noun (ojo) and adjective (negros) do not agree with each other.
the eyes belong to a woman, meaning it should be \oja negras.\

Explanation:

In Spanish, adjectives must agree with nouns in number and gender. "Ojo" is singular masculine, while "negros" is plural masculine. They don't agree.

Answer:

The noun (ojo) and adjective (negros) do not agree with each other.