Mold Identification: 8 Types, Color Chart & Photos (2026)
Identify 8 common household molds by color, texture, and location. Mold identification chart, photo guide, and what looks like mold but isn't.
You spotted something fuzzy. It's on a wall, behind the sink, or on the ceiling, and now you're trying to figure out what it is before you decide what to do about it.
Good news: most mold you'll find in a house is ordinary and something you can handle yourself. Bad news: a small number of types are serious and shouldn't be touched without the right gear. This guide covers both, with photos, a color chart, and a section on the half-dozen things that look like mold but aren't.
In This Guide
- What is Mold?: how mold grows and spreads
- Common Types: 8 types including black, green, white, and more
- Mold Identification Chart: quick-reference comparison table
- Mold vs mildew (quick summary): the short version, plus the full breakdown
- What Looks Like Mold But Isn't: common lookalikes
- Where Mold Grows: high-risk and hidden locations
- Health Risks: symptoms and who's at risk
- When to Call a Pro: professional assessment guide
- How to Identify Mold: visual, bleach test, and smell test
What is Mold?
Mold is fungus. It's outside right now, on every fallen leaf and piece of dead wood within a hundred feet of you, and that's supposed to be there; that's its job. The problem starts when it finds its way inside, lands on something damp, and stays.
How Mold Spreads
Mold makes spores, which are small enough that you're breathing some in at this exact moment. Nothing to panic about; they're in the air everywhere, indoors and out. They only turn into a visible mold patch when they land somewhere wet and don't get dried out fast enough.
What Mold Needs to Grow
Mold needs four things. Take away any one of them and it can't grow.
Moisture. This is the one that matters. If your house is genuinely dry, you don't have a mold problem. Full stop.
Something to eat. Drywall, wood, paper, fabric, even the dust on the back of your TV. If you've got a house, you've got mold food.
A comfortable temperature. 60 to 80°F. The same range you're sleeping in.
Stagnant air. Basements, crawlspaces, that corner of the closet you never open, behind the couch that's been pushed against an exterior wall since you moved in.
Common Types of Household Mold
Color and texture tell you a lot before anyone takes a sample. Here's what the most common household molds actually look like, and where they tend to show up.
Black Mold (Stachybotrys chartarum)
This is the one people mean when they say "toxic black mold." Stachybotrys chartarum is the most concerning mold you're likely to find in a house, and it's the one you shouldn't try to clean yourself.
Warning: If you think you're looking at black mold, don't poke it, don't try to wipe it, and don't run a fan anywhere near it. All three aerosolize the spores. Call a mold assessor. That's the professional who tests, not treats, and they'll confirm what it actually is.
Black mold reads as dark greenish-black, slimy when it is actively growing and powdery when it dries, and it takes hold on cellulose like drywall, ceiling tiles, and wood that has stayed wet for days. Color alone cannot confirm the species, so treat any black patch as worth taking seriously and confirm with a test rather than by sight.
For the full visual breakdown, including what black mold actually looks like, surface by surface and how to tell it apart from soot, water stains, and other look-alikes, see the dedicated appearance guide.
Green Mold (Aspergillus and Penicillium)
"Green mold" is usually Aspergillus or Penicillium. You've almost certainly met both already; Penicillium is the one behind blue cheese and penicillin. It runs from light green to dark olive, sometimes blue-green or yellow-green, powdery or fuzzy, with paler edges where it's actively spreading. You'll find it on food, on walls and insulation, in fabric and carpet, on wallpaper and painted surfaces, and cycling through the AC and ductwork (more on HVAC mold in the remediation guide). It spreads fast and covers ground quickly. Most strains are fairly harmless, but some set off allergies or breathing trouble, especially if you've already got asthma or hay fever.
White Mold
"White mold" isn't one species. It's either a mold that stays white its whole life or one that hasn't turned green, gray, or black yet. Finding it early is the useful part; it's usually the first visible sign of a moisture problem. It shows up white to light gray, powdery or fluffy, sometimes with a faint musty smell, and on concrete it's easy to mistake for efflorescence (the mineral deposits left when water wicks through masonry). Look on basement walls and floors, around wood framing, in attics and crawl spaces, on furniture, and in closets that never get air. The tell is that it appears in humid spots with no obvious leak. If it's on your basement framing, something is keeping that wood damp even if you can't yet see what.
Pink Mold (Aureobasidium pullulans and Serratia marcescens)
The pink ring in your shower isn't technically mold. Most of the time it's Serratia marcescens, a bacterium that feeds on soap scum and stays wet in the steam off your showerhead. It looks like mold, acts like mold, gets treated like mold, so people call it pink mold and move on. It's pink, orange, or reddish, slimy, usually in rings or spots, and it can darken toward brown or black as it ages. You'll see it on tile and grout, shower curtains and liners, around faucets and drains, on shampoo bottles and soap dishes, and on window sills in humid rooms. It lives on soap residue and standing water. It's not as serious as black mold, but for anyone with a compromised immune system it can cause real respiratory problems and infections, so don't wave it off just because it looks harmless.
Cladosporium
Cladosporium is the one you probably already have somewhere. It's among the most common molds in the world, indoors and out, with a trick most molds lack: it keeps growing in the cold, which is why it turns up inside refrigerators. Color runs olive-green to brown or black, the texture is suede-like or velvety, and it grows as clusters of small spots that spread outward, sometimes on both faces of a surface. Check window sills and frames, damp bathroom walls, HVAC ducts and air filters, fabric and carpet and upholstery, and under sinks around the plumbing. The standout trait is that cold tolerance, paired with being one of the top triggers for hay fever and asthma flare-ups. If allergy season feels worse inside your house than out, Cladosporium is a prime suspect.
Alternaria
Alternaria is the mold most responsible for household allergies. It hitches in on open windows, clothes, and pets, then settles wherever it finds damp, usually around condensation on windows or on a wall after a leak. It's dark brown to dark green or gray, velvety with hair-like filaments, and it spreads into large colonies with a distinctive fuzzy border. Look in showers and tubs and under leaking sinks, around window frames that sweat, in kitchens near the sink and dishwasher, on walls and ceilings after water damage, and inside AC systems. It's fast; it can take over a damp surface in a few days. It's strongly tied to allergic reactions and asthma attacks, and kids tend to react to it harder than adults do.
Chaetomium
Chaetomium is the mold that tells you something's leaking before you've found the leak. See it and don't just clean it; track down the water, because it'll grow back until you do.
It starts white or gray and darkens to olive-green or brown as it ages, with a cottony, fuzzy texture and a strong musty odor, and it often shows up next to other water-damage molds like Stachybotrys. It favors water-damaged drywall and wallboard, roof leaks and the area around skylights, basement walls after a flood, plumbing leaks inside wall cavities, and wet cardboard or paper. The giveaway is the smell; people usually notice Chaetomium before they see it, and that musty odor is often the first sign of a hidden water problem.
Mucor
Mucor looks almost like a pile of wet cotton balls. It forms thick, fluffy patches that cover ground fast, especially near HVAC vents and anywhere condensation pools, and it shows up most in homes with inconsistent climate control. It's white or grayish, yellowing to brown with age, thick and cotton-like, growing in big patches rather than little spots and turning almost pillow-like when mature. You'll find it near HVAC systems and ducts, on carpet and padding, in condensation-prone spots like cold windows and uninsulated walls, around decaying organic material, and in the soil of an overwatered houseplant.
It grows fast in warm, humid air. For most households it's a nuisance, not an emergency; but in rare cases it causes mucormycosis, a serious infection that mainly hits people with weakened immune systems, so for anyone immunocompromised it's worth taking seriously.
Orange and Yellow Mold
Bright orange or yellow growth indoors is less common than black or green, and it isn't always true mold; some of what looks orange in a crawl space is actually slime mold, a different organism altogether. Either way it means moisture has gone on long enough to surface, so it's worth dealing with.
It comes in bright orange, yellow, or yellowish-green, sometimes slimy and wet or gelatinous, sometimes powdery or a bright crusty patch. Look on wood in crawl spaces and basements, around bathroom fixtures and tile, on food and in refrigerators, on mulch near entry points, and in HVAC condensation pans. If it turns out to be slime mold (Fuligo septica), it's technically a slime-forming protist, not a mold, but that doesn't change anything for you: find the water, dry it out, and remove the growth.
Brown and Gray Mold
Most of the time brown or gray mold isn't a separate species at all; it's one of the molds above in a different life stage. Mold shifts color as it matures, so a colony that started white can go green, then brown, then black over a few weeks. Expect anything from light tan to dark brown or silvery gray, in a texture that might be powdery, velvety, or slimy, usually in irregular patches that can read like a dark stain or old water damage. Treat it like any other mold: find the moisture source first, then deal with the growth. Color on its own doesn't tell you much.
Mold Identification Chart
If you've got a spot and want to narrow it down fast, match what you're seeing against the table below.
| Mold Type | Color | Texture | Common Locations | Risk Level |
|---|---|---|---|---|
| Black mold (Stachybotrys) | Dark greenish-black | Slimy when wet, powdery when dry | Chronically wet drywall, ceiling tiles, behind wallpaper | High; call a pro |
| Green mold (Aspergillus/Penicillium) | Light to dark green, blue-green | Powdery or fuzzy | Food, HVAC systems, walls, carpets | Moderate; can cause allergic reactions |
| White mold | White to light gray | Powdery or fluffy | Basements, attics, crawl spaces, wood framing | Moderate; early sign of moisture problems |
| Pink mold (Aureobasidium/Serratia) | Pink, orange, reddish | Slimy | Bathroom tiles, grout, shower curtains, drains | Low to moderate; infections in immunocompromised |
| Cladosporium | Olive-green to brown or black | Velvety or suede-like | Window sills, HVAC ducts, fabrics, damp bathrooms | Moderate; common allergen and asthma trigger |
| Alternaria | Dark brown to dark green | Velvety with hair-like filaments | Showers, sinks, window frames, after water damage | Moderate to high; strong allergen, fast grower |
| Chaetomium | White to olive green (darkens with age) | Cottony or fuzzy | Water-damaged drywall, roof leaks, basement walls | Moderate; strong sign of water damage |
| Mucor | White to grayish, yellows with age | Thick, fluffy, cotton-like | HVAC systems, carpet, condensation areas | Moderate to high; can cause mucormycosis in immunocompromised |
One note: Color alone isn't a reliable way to pin down the exact species. Molds shift colors as they age, and the only way to know for sure is lab testing. When you need certainty, get a professional mold assessment.
Mold vs Mildew (Quick Summary)
People use "mold" and "mildew" interchangeably, but they aren't quite the same. Both are fungi, and mildew is really a flat, surface-level form of mold: white or gray, powdery, and easy to wipe off a hard surface. What people call mold is the fuzzy, raised growth that roots into drywall, wood, and ceilings and usually needs more than a wipe.
The shortcut: mildew sits on top. Mold goes in. If it's raised, fuzzy, or dark, treat it as mold. You can always downgrade your concern later if it turns out to be mildew, but it's harder to undo the other direction.
For the side-by-side table on color, texture, smell, and health risk, plus a simple at-home test and surface-by-surface guidance, see the full mold vs mildew breakdown.
What Looks Like Mold But Isn't
Before you start pulling off drywall, check whether you're actually looking at mold. A handful of ordinary household things get mistaken for it all the time.
- Efflorescence. Those white, powdery deposits on concrete, brick, or stone are mineral salts, not mold; water carries them to the surface as it evaporates through the masonry. The giveaway is that efflorescence dissolves in water, and once you fix the moisture it's gone for good.
- Dirt and soot. Dark buildup near vents, windows, and high-traffic spots feels gritty and lies flat, with none of the fuzz or slime mold has.
- Soap scum. The white-to-gray film on bathroom surfaces wipes off easily and has no musty smell.
- Water stains. Brown or yellowish rings from old leaks are flat discolorations, not raised growth. A stain can still mean a moisture problem that will grow mold if you ignore it, so don't dismiss it. And if what's on the ceiling is raised and fuzzy instead of flat, that's what mold on a ceiling actually means.
- Iron bacteria. Orange or rust-colored stains around drains, toilets, and fixtures come from iron-oxidizing bacteria in your water supply, not from mold.
- Pollen. During allergy season a fine yellow-green powder settles on sills and outdoor surfaces. It wipes away and stays gone, unless more blows in.
How to Tell the Difference
The bleach test is the fastest way to rule things in or out. Dab a drop of household bleach on the suspicious spot. If it lightens within one or two minutes, you're looking at mold or mildew. Dirt, efflorescence, and mineral deposits won't change color.
Other signs it's mold and not a lookalike:
- Fuzzy, slimy, or raised texture
- Musty or earthy smell in the area
- The discoloration keeps coming back after you clean it
- The spot has a history of moisture problems or past water damage
When the bleach test is inconclusive and the smell test isn't giving you much, a professional mold assessor can take samples and give you a definitive answer.
Where Mold Commonly Grows
If you're trying to track down where mold is likely to be hiding, start with the places that stay damp the longest.
High-Risk Areas
- Bathrooms. Near showers, tubs, toilets, under sinks, and on the ceiling above the shower. Bathroom mold guide → · Bathroom ceiling mold →
- Kitchens. Under sinks, around refrigerators, and near dishwashers.
- Walls. Along baseboards after leaks, in cold exterior corners, behind furniture. Mold on walls guide →
- Basements. On walls, floors, and around foundation cracks. Basement mold guide →
- Attics. Near roof leaks, around vents, on insulation. Attic mold guide →
- Laundry rooms. Behind washers and around dryer vents.
- Crawl spaces. On floor joists, vapor barriers, and supports. Crawl space mold guide →
Hidden Locations
A lot of mold grows where you can't see it:
- Behind drywall and wallpaper
- Inside HVAC ducts and systems
- Under carpeting and padding
- Behind cabinets and furniture
- Inside wall cavities around plumbing
- Beneath flooring materials
Signs of Hidden Mold
You can't see it, but these are the signs it's there:
- Persistent musty or earthy odors
- Visible water stains on walls or ceilings
- Peeling or bubbling paint or wallpaper
- Warped or buckled flooring
- Chronic allergy symptoms that improve when away from home
Health Risks Associated with Mold
How mold affects you depends on three things: how sensitive you are, how much exposure you've had, and which mold it is. For a fuller breakdown of symptoms by mold type, short-term vs. long-term effects, and when a doctor visit is warranted, see our mold exposure symptoms guide.
Common Symptoms of Mold Exposure
Most people get mild symptoms:
- Nasal congestion and runny nose
- Sneezing
- Eye irritation (redness, itching, watering)
- Skin rashes or irritation
- Throat irritation
- Coughing
- Headaches
More Serious Reactions
Some people get hit harder:
- Difficulty breathing or shortness of breath
- Fever
- Chronic fatigue
- Memory problems or difficulty concentrating
- Persistent sinus infections
If you're in a high-risk group (compromised immune system, chronic respiratory condition, severe allergies, or asthma), you're at much higher risk from mold exposure. Don't try to handle anything beyond a small patch yourself, and see a doctor if symptoms develop.
When to Call a Professional
A patch under 10 square feet is usually something you can handle yourself. Bigger than that, or in the situations below, you need a pro. Not sure which side of the line you're on? DIY vs. professional removal →
Call a Professional Immediately If:
- The patch is bigger than 10 square feet. Larger growth needs professional containment, not a spray bottle.
- You think it's black mold. The health risk is too high to gamble on a DIY cleanup.
- It's in your HVAC system. The ducts will carry spores into every room.
- There's been sewage backup or contaminated water. That stacks a category of health hazard on top of the mold.
- It keeps coming back after you clean it. Something is still feeding it with moisture.
- Someone in the house has symptoms, especially respiratory ones.
- You can smell it but can't find it. Hidden mold takes professional detection to locate.
When you're not sure, call someone. A professional mold assessment is affordable and it's a lot cheaper than the health or property damage that comes from guessing wrong.
What a Professional Assessment Actually Involves
A certified mold assessor will:
- Conduct a thorough visual inspection
- Use moisture meters to detect hidden water issues
- Collect air and/or surface samples if needed
- Identify the moisture source causing the problem
- Provide a detailed report with remediation recommendations
Choosing the Right Professional
Here's what to look for:
- State licensing (required for mold assessors in many states)
- Current insurance coverage
- Verifiable certifications from recognized organizations like IICRC
- Detailed written assessments, not just verbal opinions
- No conflict of interest. The assessor shouldn't also be doing the remediation (here's why that matters)
For the full process, see our hiring guide, along with questions to ask and scams to avoid.
How to Identify Mold in Your House
Mold identification comes down to three things: what it looks like, where it's growing, and whether it passes a simple test.
Visual clues:
- Fuzzy or slimy texture. Mold is raised from the surface; dirt and stains lie flat.
- Irregular patches. Mold spreads outward from a moisture source in organic, splotchy patterns.
- Color. Green, black, white, brown, orange, or gray. Use the chart above to narrow it down.
- Growth pattern. Mold follows water. If the discoloration is clustered around pipes, windows, HVAC vents, or old water stains, you're probably looking at mold.
The bleach test. Dab a drop of household bleach on the spot. If it lightens within 1–2 minutes, it's mold or mildew. Dirt and mineral deposits won't change color.
The smell test. Mold has a distinctive musty, earthy odor. If a room smells damp even after you've cleaned it, there's probably hidden mold behind a wall, under flooring, or in a ceiling cavity. For a fuller breakdown, including what different molds smell like and the everyday odors people mistake for mold, see what mold smells like.
When you still can't tell. A professional mold assessor has moisture meters, thermal imaging, and air sampling that can confirm what's there and what species it is. That's when it's time to bring one in.
Next Steps
If you're pretty sure you've got mold, here's the order of operations:
- Document what you see. Photos and measurements of the affected area.
- Find and fix the moisture source. Mold can't survive without water. If you don't fix the leak, nothing else matters.
- Don't disturb it. Poking, wiping, or fanning mold aerosolizes the spores.
- Measure the patch. Under or over 10 square feet?
- Decide your approach. DIY for small patches of common mold. Professional for anything larger, any suspected black mold, or anything in an HVAC system.
Find a Verified Mold Professional
Your home and your health are both on the line, so don't hire the first name that shows up. Find a verified mold inspection company in your area. Every professional we list has been vetted for proper licensing, insurance, and reputation.
📚 This guide is part of our Complete Mold Remediation Guide. Your full resource for understanding, preventing, and removing mold.
Frequently Asked Questions
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If what you found needs a pro, you can browse verified mold remediation companies. Every contractor is identity-checked and tier-ranked, with licenses, insurance, and reviews verified where available.
This guide is for educational purposes only. Always consult with certified professionals for specific mold situations in your home. If you experience health symptoms, please consult a healthcare provider.