Molds that are red or orange in appearance are harmless, although they sometimes causing allergy symptoms when inhaled into nasal passages. They are found in outdoor conditions. Growing on dampened wood and decomposing plants, they are removed for aesthetic purposes.
Molds are a type of fungus that grows indoors and outside. They thrive in warm damp humid conditions. Molds use spores for reproduction, and their spores can survive in severe environmental conditions. Some molds release spores in only hot, dry weather. Both indoor and outdoor molds are associated with allergies. Symptoms may continue year round due to the ability of molds to remain dormant during cold winter months.