With the exception of catnip., and sometimes in the wild- grass- to relieve stomach problems ( one wishes people had such instinctive insight) Cats are carnivorous that is meat-eating by nature....
No. My uncle used to have a cat that loved to eat oranges. Most cats, however, hate the smell of anything citrus (lemons, limes, oranges, grapefruits). Perhaps that is what you're thinking of?
A cat's temperament has nothing to do with its coat colour. It defends if you are nice or if its mean it is mean cos it may been a cat who was owned and been left and brought to the pet shop.