Mold Tips: How Many Colors Does Mold Come In?

Mold comes in all shapes, sizes, and colors, and while some may think that color can be used as an identifying feature, unfortunately, it is not.

The main means of identifying mold is to look closely at its structure, spores, and growth form, which is not easy to do without access to the laboratory.

Color is not a good feature for distinguishing mold or its toxicity, as a patch can have multiple colors, or change color for multiple reasons. Some factors that affect mold color are the type of food, humidity level, and light conditions.

No matter what color the mold is, if it shows up in your house, the humidity in the room is probably high and should be removed as soon as possible. Here are the colors of mold you might find in your home.

Green Mold

Green is the most common color of mold. There are hundreds of thousands of types of mold, thousands of which turn green at some point in their lives. When it comes to green molds, it is likely to be one of these Aspergillus, Penicillium, and Cladosporium.


Black Mold

Black mold is a notorious member of the mold family, but not all black mold is toxic.

While it's important to get rid of all mold as soon as possible, treatment with toxic black mold should be handled by professionals. 

Several different types of black mold can be found in your home on a daily basis, so noting certain features can give you an idea of how urgent it is to get rid of them.


  • Stachybotrys 

Stachybotrys chartarum (S. chartarum) is a notoriously toxic black mold. It usually appears black or greenish-black and can grow in leaky areas, old rotting wood, paper and food.

S. chartarum needs constant moisture to grow, so the faster these areas are resolved, the less of a threat it will be. 

You might find black mold in a house after a flood, or where the roof is leaking. What makes S. chartarum so dangerous is that it produces a fungal called mycotoxin, which can be sprayed into the air and inhaled by humans and animals.

Exposure to mycotoxins produced by S. chartarum can cause headaches, sneezing, coughing, rashes, and sometimes even blood poisoning.

  • Alternaria

It is crucial to realize that the black mold could be S. chartarum, but it is also highly likely to be Alternaria, which is much less dangerous.

Alternaria usually grows outdoors in dusty, wet places, near plants and soil. Recently, though, it was discovered that they might be growing in houses. 

Exposure to Alternaria may exacerbate asthma, but other than that, it doesn't pose many health risks.

  • Aspergillus

Aspergillus is another common fungus, and studies have shown that humans actually breathe in large amounts of Aspergillus every day. High exposure can cause aspergillosis and other respiratory problems. 

  • Cladosporium

The black mold in your home can also be a type of Cladosporium, which usually grows outdoors on decaying leaves.

It can also be found indoors and takes up residence on walls, insulation and carpets, and exposure to it can sometimes cause rashes, eye irritation and sinus infections.

Purple Mold

Purple isn't a common mold color, but if you see it, it's probably a variant of the poisonous Stachybotrys chartarum.

White Mold

White is another common color of mold that grows in your home, and it can be one of several different types.

  • Alternaria
Any white mold found in your home is most likely Alternaria. It also shows that a mold can change color depending on conditions.
  • Chaetomium

Chaetomium is a mold that can grow anywhere and is highly adaptable and resilient.

It can grow on many hosts, but it prefers wet, dark places. Some might describe it as having a cotton-like appearance, while others might write it as a salt stain on a basement wall.

One of the distinguishing features of Chaetomium is its smell. It's often the culprit behind the musty smells you might smell in basements, attics, and food.

  • Penicillium

Penicillium is another polychromatic fungus that can sometimes be white. The discovery of Penicillium was an important step in the field of medicine because it led to the creation of penicillin.

It can be found in foods and on walls with high humidity, and while it is an important component of penicillin, it can cause severe allergic reactions if not handled properly.


Blue Mold

Blue is another common color of penicillium species found on food and walls.

Pink Mold

If your shower curtain or bathtub hasn't been cleaned in a while, you may find a pink film on them, which is known as "pink mold." 

Calling it a mold is a misconception, though, because it's actually a bacterium called Serratia marcescens that grows on soap residue.

There's no permanent solution other than cleaning your bathroom regularly, but while it can lead to urinary tract infections and respiratory problems, fortunately it's not easily infected.

Yellow Mold

Yellow is a color to watch out for, as some of these molds can be dangerous if left unchecked.

  • Aspergillus

Sometimes Aspergillus can appear yellow. As mentioned earlier in the Black Mold section, this is a mold type that is very common in houses and basically low risk.

  • Serpula Lacrymans

Serpula lacrymans is not dangerous to humans, but it has a great impact on the wood structures.

This fungus is an excellent destroyer of wet and decaying organic materials and can spell disaster for your house if not removed. It grows rapidly and, if conditions are ideal, can easily devour wood surfaces both indoors and outdoors.


  • Epicoccum Nigrum

Epicoccum nigrum is a fast-growing yellow mold that can be found on damp drywall, mattresses, wood, carpets and furniture. Its color varies from yellow to orange to brown, depending on conditions and surroundings.

  • Geomyces Pannorum

Geomyces pannorum is a more unique fungus than the others on this list in that it only grows in cooler conditions.

This means that in the northern hemisphere, it can basically only grow on damp walls, floors, wood and paper.

  • Yellow Slime Mold

If you encounter a sticky bright yellow mold in your home, stay very far away from it. Try not to touch it or breathe it in. 

The bright yellow mold is usually not real mold, but an unrelated organism called "slime mold."

Slime mold can be very toxic and should not be touched lightly. None of the other yellow molds on this list are bright yellow, they are more like white or brownish-yellow, so yellow slime molds should be easy to tell apart.

Red Mold

You may find red mold on building materials such as particleboard or drywall that have suffered water damage.

Red is not usually a consistent color for mold, and it usually changes over time. Many types of mold turn red at some point in their lives, but because of its ubiquity, it is most likely Aspergillus. However, if you find red mold on your food, it's probably neurospora.

Orange Mold

Orange mold is similar to Serpula lacrymans in that it is a fast growing mold that can cause severe damage to wood structures over time.

It is often found inside or outside homes on wooden surfaces such as tables, chairs, beams and floors. Exposure to orange mold may worsen asthma and other respiratory illnesses, but it generally poses little health risk.

Brown Mold

Brown is another color that may be present in several different mold groups.

Many brown molds can spread quickly on harder surfaces, and while they may cause allergies in some people, they are largely relatively safe. Many of such molds have a very foul smell. 

Brown mold can be any of the following types: Pithomyces chartarum, Aureobasidium pullulans, Stemonitis, Cladosporium and Mucor.

While brown mold is generally safe when it comes to it, Mucor mold is an exception.

Mucor is a very dangerous type of mold that grows around and sometimes causes life-threatening blood infections called mucormycosis.

It is a mold that is difficult to distinguish because it can be brown, yellow, black, white, or gray at any point in its life cycle.


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