I searched something about these Blue Mold, I hope these will be beneficial for you; Penicillium is a name that often strikes people as familiar, and that is because modern antibiotics were discovered thanks to a species of Penicillium long ago. However, that doesn?t mean that the genus can?t be hazardous. It can look blue, green, or white, and its species are generally classified as B or C. It can be found on foods, such as cheese and fruit, or in the walls, the insulation, and other places.