How To Cover the Challot

On Shabbat (and Jewish festivals), you should place a white cover above the challot and another below (unless you have a white tablecloth).
Reason To recall the layers of dew above and below the mun that the Israelites ate for 40 years in the desert.
Note If you have a fancy or beautiful cover for your challa that is not white underneath, you may put a white cloth or paper towel between the cover and the challa in order to have a white cover above the challa.