Question

Leela's face became red. (Negative)

Answer 1

Leela's face became red. In this sentence “red” is an adjective, meaning “Leela's face became red in colour.” If you want to convey the same meaning using “red” in a verb form, then the sentence should be changed as “Leela's face reddened.

Answer 2

Leela's face became red =) Leela's face became red in colour.

So, Negative form: Leela's face was not in normal colour.

I am not sure for this answer, but yet tried to solve.....