Your kitten could have an eye infection. To clean it off, you need to get a warm wash cloth and gently wipe the kittens eye away from it's face so you won't get anything in the other eye. But if it does not go away you might have to see a vet. Good luck and God Bless:)
No. Their eyes are yellowish.
Kittens open their eyes in approx. 7 to 10 days.
yes kittens they can get colds in there eyes
Not all of them but some have yellowish green eyes.
I believe they are yellowish
Shorthaired kittens will open their eyes 5-8 days after birth, and longhaired kittens will open their eyes 10-14 days after birth, usually.
Usually, all kittens are born with blue eyes, but the color will change, depending on the breed. Siamese kittens keep their blue eyes, but most others don't.
That your cat has green eyes
jaundice
Take them for treatment by an animal doctor (a vet) if you can not afford one then there are bound to be some charity Vets around.
Let it sleep?
Yes.