grammatical number - Is using "their hairs" grammatically wrong?

I'm Soumya, an author from India.

A reader has challenged me about the use of the word 'hairs' in my book. I have used, 'a few hairs' and that's justified, as hair is a countable noun in that very phrase. But I'm at a confusion for some other sentences. Could you kindly tell me if I'm wrong grammatically?

1. "The evening zephyr ruffled their long flowing hairs - the Indian village girl's shiny, black hair, and Audrey's curly blonde hair."




2. "They had golden or brown or ashen hairs."




3. "His black and white hairs had now turned into complete white."

Could you please help? Thank you!