Color fading of your aquarium fish might be a serious problem as we all love their vibrant magnificent colors. So let’s find out why your fish getting pale or changing color and how to avoid it.

What causes a fish to lose color?

The main reason that fish will lose their color is usually due to stress in their environment. In addition, several environmental factors and lack of care of their owners also may cause color changes of aquarium fish. Here is a list of possible root causes for the color fading of aquarium fish.

  1. Stress
  2. Lack of Nutrition
  3. Diseases
  4. Color Fed Fish

Why do fish get stressed?

Stress in your fish can have a lot of potential root causes. So you should narrow down and figure out what the exact cause is. 

Stressed fish

Environmental Changes

First up, maybe you just bought your fish. Sometimes introducing a fish into a new environment can cause the color to fade. This can especially be a problem when fish are shipped to your home. 

Poor Water Quality

Poor water quality is the next main reason for your fish to lose can really wreak havoc on your fish. So this is one of the first things that you should check if your fish is suddenly experiencing a loss of color. 

The presence of ammonia or too high nitrates can be very toxic to fish. Along with this other factors such as too low or too high of a water temperature in the aquarium, large temperature fluctuations in the tank, keeping your fish in too high or low of a pH for that species, too high of Nitrites or phosphates can also cause color loss in your fish. 

So it’s important to make sure that you are testing your aquarium water and know where the water parameters are. So that you can make sure that your aquarium water quality is right where it needs to be at all times.

Tank Bullies

One of the next big reasons that your fish gonna stressed and lose color is tank bullies. Often the fish that’re being bullied or picked on by other fish will start to lose their color. The fish may even become so stressed. They might actually start to darken in color or even appear to turn black. 

Keeping an eye on the behavior of the fish in your aquarium can really help you to determine whether your fish are compatible with each other. If this is a problem that fish is need to be separated and may be placed in a separate tank.

Also at the same time, some aquarium fish varieties like tetra are known as schooling fish. Those kinds of fish need at least five to ten fish per a school.

Tetra Fish Schooling
Tetra Fish Schooling

Inappropriate Tank Setups

Finally, your fish may become stressed due to uncomfortable tank setups. Each fish has its own preffered tank setups like planted or black water setups. It includes the lighting condition, tank size, tank decorations, and many more factors. So you should do a research regarding each fish to underestand what type of tanksetup needed for that particular fish.

Lack of Nutrition

Aquarium fish foods
Aquarium Fish foods

Poor Diet and lack of nutrition is the other main factor that causes color loss in aquarium fish. Feeding your fish incorrectly such as a diet too high or low in protein can be a contributing factor to color loss depending on the species that you’re keeping. 

Always do research regarding the species of fish that you’re keeping to make sure that they are receiving adequate nutrition for that specific species.


aquarium fish with diseases
Aquarium fish with fungal infection

Your fish may also lose color due to an underlying illness. If the loss in color in your fish is accompanied by other symptoms such as brain fins, white spots, flashing where it’s rubbing itself on ornaments or gravel, bloating, odd swimming behavior, or any other potential symptoms this fish might need to be treated for an illness. Once the fish is fully recovered from the illness their colors should begin to return.

Color Fed Fish

If all the above factors are Ok but still your fish losing color, probably you might have tricked at the store and bought a dyed fish. Most probably those fish have been color fed.

Color fed tetra fish

Unfortunately, this is a thing that happens in the aquarium hobby. Naturally, those fish are not much vibrant or flashy as you see in the pet store. So if you buy these dyed fish or you’ve already bought them, in a matter of a few years that colors gonna fade away and you’ll be left with a paled white fish.


I hope this information really helps you to determine why you might be seeing some color loss in your aquarium fish. Now you have an idea of what you can do going forward to keep that beautiful vibrant color in your fish. So do the right thing and take care of your fish, they will heal your mind with their beautiful colors.


I am Chamika who is an aquarium hobbyist for nearly a decade. My aim is to help fishkeepers get accurate and helpful information regarding every aspect of fishkeeping.

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