Oil based paints (oilpaint) which give glossy finish have a very strong odour that takes a minimum of a week to become bearable. Other paints...well, around a week but bearable within 3-4 days. Unfortunately, I do not have a lot of knowledge on the subject. I think Acrylic Emulsions are good.
Distemper paint discolours and shows up as dirty looking blotches in some areas within 5-6 months but is cheaper.