We've all already junked some chocolate because it turnd white or gray, thinking it was old? The question ... Have we made a mistake?
This whitish coating which may appear on the surface of the, is called the fat bloom, resulting in changes in fat of the chocolate, and the sugar bloom, formed by the action of moisture on the ingredients of sugar.
The chocolate that has "bloomed" is still safe to eat (because it is a non-perishable food because of its sugar content), but may have an unappetizing appearance and surface texture.
In general, the chocolate bloom can be "fixed" by melting the chocolate down, stirring it, then pouring it into a mold and cooling it, collecting the sugar or fat in the solution.
It is the humidity, the heat and the condensation that causes the change of color. Chocolate should ideally be stored in an airtight container at about 70 degrees.
So if you find white stains on your chocolate, no worries! Chocolate remains perfectly edible and this does not affect (too much) taste. The chocolate also keeps all its properties.