Almost like clockwork at the start of each year, top paint manufacturers debut their new color schemes and trot out their "it" colors. Coral Reef, Springtime Dew, Guildford Green, Pink Ground; so tempting - and sure to perk up a home, especially in the winter doldrums. Conventional wisdom says paint is the easiest, least expensive quick-change artist in a homeowner's tool box. Problem is, as with much conventional wisdom, it's not quite so ...