Common Types of Mold Found In Your Home

As a Licensed Mold Assessor, I’ve seen mold in every color of the rainbow — and yes, color really does matter.

While mold color alone doesn’t always determine its toxicity, it can give you valuable insight into what kind of mold you’re dealing with, how dangerous it is, and what to do next.

💡 Want to learn how to confirm mold in your home?
👉 Start here with mold detection basics
👉 Explore mold testing options

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🖼️ Visual Guide: What Different Types of Mold Look Like

Here’s how to visually identify common household mold colors. Note: appearance alone can’t confirm if mold is toxic, but it helps narrow it down.

Mold Type	Color / Texture	Common Locations
Black Mold	Dark green to black, slimy	Drywall, ceilings, wood, insulation
White Mold	Fuzzy, powdery, or chalky	Crawlspaces, basements, wooden studs
Green Mold	Fuzzy, velvety, often patchy	Bathrooms, windows, food
Orange Mold	Gel-like, orange-pink tint	Shower seals, toilets, under sinks
Yellow Mold	Dry, dusty, mustard-colored	Wallpaper, HVAC units, wood

🎨 Mold Colors and What They Mean

Black Mold

Stachybotrys chartarum is the infamous “toxic black mold.” It’s slow-growing, thrives on cellulose-rich materials like drywall, and produces potent mycotoxins. Always treat black mold as a serious health hazard.

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White Mold

White mold can appear powdery or fuzzy and is commonly found in crawlspaces, basements, and on wood. It’s often confused with mildew and may change color as it matures.

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Green Mold

Often caused by Penicillium, Aspergillus, or Cladosporium, green mold is fast-growing and shows up on drywall, carpets, or spoiled food. While not always toxic, it’s aggressive and allergenic.

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Orange Mold

Slimy and bright, orange mold is usually Acremonium. It grows in dark, wet areas like behind walls and on insulation, especially after long-term leaks.

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Blue Mold

Caused by Penicillium species, blue mold appears on fruits, bread, or water-damaged building materials. It can produce the toxin patulin and should be avoided.

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Red Mold

Mold species like Neurospora, Rhodotorula, and Aspergillus can appear red. It often grows in bathrooms or on food, especially when ventilation is poor.

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Grey Mold

Commonly associated with Botrytis cinerea, grey mold thrives in cool, damp environments like plant matter, wallpaper, or cold corners of the home.

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Purple Mold

Purple mold is rare but may appear on fabric, insulation, or decaying materials. It could signal Fusarium or Chaetomium, both of which can produce mycotoxins.

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Pink Mold

Usually not a mold at all, pink “mold” is Serratia marcescens, a bacteria found in bathrooms and wet areas. It still poses health risks and should be cleaned promptly.

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Yellow Mold

Dry rot fungus like Serpula lacrymans, along with Aspergillus and Epicoccum, can cause yellow mold. It grows on wood, insulation, and spoiled food and may be crusty or slimy.

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🔬 Most Common Indoor Mold Species

These are the mold genera you're most likely to encounter during an inspection or remediation.

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🧫 Penicillium

Found on food, fabrics, and water-damaged drywall, Penicillium is fast-growing and can produce allergens or mycotoxins.

• Colors: Blue, green, white
• Grows on: Furniture, walls, food, insulation
  👉 See Penicillium-related green mold

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🧫 Aspergillus

One of the most common indoor molds. Found in HVAC systems, insulation, and wet fabrics, and known to cause allergic reactions and respiratory issues.

• Colors: Yellow, green, brown, black
  👉 Read more about Aspergillus and black mold

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🧫 Alternaria

Common in bathrooms, windowsills, and wet areas, Alternaria spreads quickly and is highly allergenic.

• Colors: Dark green, brown, gray
  👉 Compare with white and grey mold

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🧫 Stachybotrys (Black Mold)

The most infamous indoor mold. It requires prolonged moisture and grows on drywall, ceiling tiles, and wood. Produces dangerous mycotoxins.

👉 Learn how to identify toxic black mold

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🧫 Chaetomium

Chaetomium is often found after water intrusion, especially in wall cavities and on subfloors. It can look greyish or black and may smell musty.

👉 See how it relates to purple mold

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🧫 Cladosporium

Grows on dusty surfaces, leather, vents, and fabrics. Not toxic, but a strong allergen.

👉 Compare with green mold found in HVAC systems

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🧫 Fusarium

Grows even in cool environments, and can spread rapidly through fabric, carpet, and food. Often pink or purple in appearance.

👉 Learn about Fusarium-related pink and purple mold

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🧫 Trichoderma

Thrives on wet wood, insulation, and wallpaper glue. Known for its destructive capabilities and mycotoxin production.

👉 See Trichoderma growth in green and white mold

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🧫 Memnoniella

Closely related to Stachybotrys and often mistaken for it. Found in wall cavities, paper, and insulation.

👉 Learn the difference between Memnoniella and black mold

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🧫 Ulocladium

Grows in flood-damaged areas and requires heavy water exposure. Can often be a marker of past serious leaks.

👉 Compare Ulocladium and grey or black mold

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✅ Final Thoughts from Brad

Color isn’t everything — but it’s often your first clue that mold is growing somewhere it shouldn’t.

If you spot any of the above in your home:

• 🧪 Consider getting a mold test
• 🧰 Schedule a mold inspection
• 📚 Read how to remove mold safely

Don’t wait — the longer mold grows, the more damage it does.

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