Types of Mold in Homes
Black, white, green, and the species behind them — what each looks like, where it grows, and which ones to worry about.
| Type | Appearance | Where it grows | Concern |
|---|---|---|---|
| Stachybotrys ("black mold") | Dark green/black, slimy | Chronically wet drywall, wood | High |
| Aspergillus | Green, white, or yellow | Walls, insulation, HVAC | Moderate–high |
| Penicillium | Blue-green, fuzzy | Water-damaged materials | Moderate |
| Cladosporium | Olive-green to brown/black | Bathrooms, fabrics, ducts | Moderate |
| Alternaria | Dark green/brown, velvety | Showers, sinks, damp spots | Allergenic |
Color isn't the whole story
"Black mold" is a look, not a species — plenty of dark molds are harmless, and some dangerous molds aren't black. If you need to know exactly what you're dealing with, a lab test settles it.
What they all have in common
Every type needs moisture. Whatever the species, the fix is the same: remove the mold safely and eliminate the water source so it can't return — our remediation process.
Questions, Answered
Types of mold FAQ
The most common are Cladosporium, Aspergillus, Penicillium, Alternaria, and Stachybotrys (often called toxic black mold). They vary in color and risk.
Stachybotrys chartarum and some Aspergillus species are the most concerning for health, but any mold can trigger allergy and respiratory symptoms and signals a moisture problem.
Color is a clue, not a diagnosis — many species share colors. Lab testing is the only reliable way to identify the species.
Got mold? Let's get it gone.
Free same-day inspection, certified remediation, and we handle the insurance paperwork. Talk to a Denver mold specialist now.