Yellowing: aging paint surface appear yellow; the white paint and varnishes dry most obvious.
● alkyd paint, oil paint or varnish peroxide.
● from the stove, heater, heating pipe heat.
● lack of light (for example, after the portrait or household appliances, inside closets, etc.).
Workaround: high-quality latex paint will not yellowing, non-yellowing varnish is not easy to yellowing. Alkyd because of its curing, the yellowing is likely, especially in some parts are not visible light.