his hands' color is red - This is what I wrote. Isn't it also correct?
Sounds find to me. Report it.
Caught him red handed!
Does " उसके हाथों लाल है। " (his hands are red) have the same meaning ?
no, हाथों as a plural is only used in the oblique (with postpositions like का or को etc.). The regular form of the plural is just हाथ. So it would be: उसके हाथ लाल हैं
i put "her hands" and duolingo said it was incorrect. Is there any way to tell the sex of the person in this sentence?
The colour of her hands is red is accepted now
I think , as there is a plural word"hands" so are we not supposed to use "are" instead of "is"?
The colour (of his hands) is red. You would say "His hands are red" or "The colour is red", but in this sentence, colour is the subject, not hands.
Is it supposed to be " the colour of his hands are red. " ?
No. Colour is the subject of the sentence. You would say "are" if you were just saying "His hands are red." If you take out "of his hands" then it would be "The colour is red."