Common Types of Mold Found In Your Home

By: Licensed Mold Assessor Brad Fishbein

February 3, 2023

As a Professional Mold Assessor, I am here to guide you through the diverse and colorful world of mold which is an important step in detecting the type of mold you may have. These microorganisms come in a wide range of colors, each with its own distinct characteristics and behaviors. We'll delve into the different colors of mold and provide you with essential information on each type. Whether you're dealing with a mold problem at home or simply want to expand your knowledge of these fascinating fungi I got you covered.

Common Colors of Mold

  1. Black Mold aka Stachybotrys is a fungus that is known for being a slow-grower and thrives in damp environments, particularly on porous building materials. Not only does it have a unsightly appearance, it can also produce harmful mycotoxins that can impact both human and pet health. And, Stachybotrys may not always appear as only black, it can also be found in shades of green and gray.

  2. White Mold loves to thrive in moist areas of the home like showers, basements, and crawl spaces. If it has a steady source of food, like wood, it can spread rapidly and cause significant damage. You might mistake it for mildew, but white mold can change colors as it produces spores and may appear white, green, or grey. Keep your home dry to avoid this moldy invader.

  3. Green Mold is a type of fungus can come in different species and usually has green spores from genera like Cladosporium, Aspergillus, and Penicillium. You'll know it when you see it - green mold looks like soft, fuzzy, or powdery growth in shades of green. It's not picky about where it grows either - it's happy to munch on any food it can find, like fruits and bread. Gross! Keep an eye out for this moldy menace and make sure to properly store your food to prevent it from appearing.

  4. Orange Mold loves damp, dark places and is easy to spot with its bright orange color and slimy texture. It's part of the Acremonium strictum group, which includes molds found in soil, wood, and decaying plant material. It is more often found outdoors than indoors.

  5. Blue Mold is sometimes caused by Penicillium expansum among other types of Penicillium. Blue mold can often be found on food. It can also grow on household materials and furnishings that have been damaged by water, as well as plants with wounds. If you see circular lesions on your plants, beware - blue mold can produce toxins, including patulin, that can make you sick if ingested.

  6. Red Mold refers to molds that may exhibit a red color, such as Aspergillus, which is commonly found in damp bathroom environments on water-damaged materials; Neurospora, which is often found on food; Rhodoteorula, which is commonly found in milk and fruit juice; and Fusarium, which can be found on plants and in soil. These molds are not a specific type, but may appear red in color.

  7. Grey Mold

  8. Purple Mold

  9. Pink Mold

  10. Yellow Mold

Common Mold Species


Penicillium is one of the most well-known types of mold. But here’s the thing: It’s not all bad! Penicillin is actually derived from Penicillium mold. Blue cheese is made from Penicillium mold as well. Does that mean you want it growing on your walls, clothes, furniture, etc? No... For the most part, Penicillium is high amounts is just allergen mold, however, there are certain strands that can be toxic. Penicillium is probably one of the fastest growing species of mold that will start to form on water-damaged building materials. Penicillium can grow on water-damaged areas in many different colors such as blue, green, white and black.


Aspergillus mold is usually classified the same as Penicillium because it is so hard to differentiate the two under a microscope. It is also very commonly found indoors as well as outdoors. For the most part, Aspergillus will be allergenic, but there are a few strands that can become toxic. It is known to cause upper respitory issues in humans when present in large amounts. Aspergillus is very fast growing, It is one of the first species of mold that will start growing on water damaged walls and contents throughout the home. Aspergillus will generally be yellow, brown, green or black.


Alternaria is considered one of the most common species of mold in the entire world. It can show up indoors but is much more common outdoors. When found indoors, it is mostly found in the bathroom and can easily be cleaned. However... Alternaria can also be found on water-damaged building material. While it is an allergenic mold, it can cause some unwanted symptoms in humans and animals such as upper respiratory issues. Alternaria will usually appear as green,grey or brown.


Stachybotrys may as well be known as "The King Of Molds. When you hear the term Black Toxic Mold, it is being referred to as Stachybotrys. Stachybotrys is considered a slow growing mold that needs a ton of water over an extended period of time to grow and thrive. Stachybotrys itself is not toxic, it is the mycotoxins it produces. Serious health effects have been linked to Stachybotrys... Meaning: If you have any of it growing in your home, it needs to go! And it needs to be done by a licensed mold remediation professional as trying to remove Stachybotrys yourself can make the problem even worse! It can be lethal for infants and people with compromised immune system Stachybotrys will usually be black or green in color.


Chaetomium mold may not produce mycotoxins to the level that Stachybotrys does, but you do not want to fool around with Chaetomium because it absolutely can cause mycotoxins. It is also known to possibly cause nail infections. Chaetomium tends to be found in areas of water damaged wood such as carpet tack strips, roof sheathing and furring strips. Chaetomium will grow only on heavily water damaged building materials. It will usually appear as white, black, or grey. If you have Chaetomium in your home, it needs to be removed ASAP by a licensed mold remediation professional.


Cladosporium is extremely common indoors. It is also very common outdoors. It can usually grow in colder climates than most species of mold. Cladosporium is commonly found within the HVAC system. It grows on dust with ease. You know those little white spots you see on some of your shoes or leather items? Say hello to Cladosporium! Cladosporium is not known to be toxic but it can cause upper respiratory issues in people that have allergies to it or have an at-risk immune system. Cladosporium shows up as green, white, black, and even brown. You don't want Cladosporium in your home in large abundances.


Fusarium is one of the bad guys you do NOT want to see growing in your home. It has been called the "what" mold. Why is it called that? Because there have been reports linking Fusarium to short-term memory loss. Fusarium can grow in colder temperatures. It can absolutely be toxic so it needs to be taken seriously. Fusarium can be grow on cellulose based building materials but is more commonly found on fabrics. It also found in some food. Fusarium can be pink, orange,white, or purple. Fusarium can spread quickly through the home which is another reason to dry up any water damaged building materials very shortly after a flood!


Trichoderma in the home can be a nuisance. It is very fast growing mold that grows on wet surfaces such as wallpaper, carpet and porous furniture. It abosolutely destroys wood as well. It is NOT a mold you generally want to see indoors. Trichoderma can be both allergenic as well as toxic. When it does produce mycotoxins, it can act very much like Stachybotrys on building materials. Trichoderma can be very dangerous for people on dialysis as well as liver transplant recipients. Certain strands can show up on food, specifically sweet potatoes. Trichoderma will usually be white, blue or green in color. It THRIVES on wet, porous items, so if you have a leak, don't let the water sit too long without drying it!


Memnoniella is very similar to Stachybotrys. I guess you can say it's Stachybotry's evil brother! Not as much is known about Memnoniella, however, there is one thing for sure... It can be very dangerous! It produces mycotoxins and can have some adverse health effects on humans who breath or ingest it. Memnoniella thrives on cellulose-based products such as drywall. It is very dark grey or black. Memnoniella is very slow growing. If you had Memnoniella in your home, it did not get there over night! It simply needs to be removed by a licensed mold extraction company.


Ulocladium as with most species of mold Ulocladium loves it some water! It needs much more water than other molds listed above! That is why Ulocladium is not as common as most of the species on this list. It tends to be present in textiles and paper products. Ulocladium is very commonly found on particle board when it gets severly water damaged. Ulocladium does not produce any known toxins but can still affect humans. It is known to produce a possible tissue infection. You will generally see Ulocladium appear as brown, but can also be black and green.

Meet the author: Brad Fishbein is an ACAC council-certified Microbial Investigator. In the fall of 2012, he became a Licensed Mold Assessor in the State of Florida through the Department of Business & Professional Regulation. Brad has helped homeowners with over 5,000 successfully completed Mold Inspections since 2009.

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