Why Do Discus Fish Change Color?

It is pretty shocking when you see your beloved discus change color, isn’t it? Once, I was feeding my discus fish and one of them turned from green to brown right in front of me. I almost dropped the fish food!

Anyway, discus fish usually change color as a way to camouflage and protect themselves from predators. Additionally, their colors can shift according to the temperature or water quality.

In this guide, I’ll explain why discus fish change color and how you can help your fish maintain their vibrant colors. So, keep reading to learn more!

Reasons Why Discus Change Color

Bad Water Parameters

One of the biggest challenges for those who keep discus fish is maintaining ideal water parameters. If discus fish are not up to par, it can adversely affect your fish, causing them to change color.

To be honest, I had a very hard time trying to keep my discus fish healthy and their colors vibrant.

I would constantly see them changing color, no matter what I did. It wasn’t until I learned about water parameters that things started to make sense.

Here are some water parameters that you need to keep an eye on:

Poor  Diet

Young discus fish color may change when do not get enough protein in their diet. Ideally, they need a diet containing 35-45% protein when they are young or newly hatched fry.

While juvenile discus fish need up to 50 percent protein, once discus fish become adults, their diets should contain around 40 to 45 percent protein.

Insufficient amounts of vitamins, fibers, and minerals in their diet can also lead to color loss or fading.

To ensure that your fish are getting the nutrients discus fish need, give them live or frozen foods, such as:

Old Age

Losing or changing colors isn’t necessarily mean that something is wrong with your fish. It could just be a sign that they are getting old.

When your discus fish reaches 5-6 years old, you may start to see their colors gradually fading.

As these guys age, their metabolism starts to slow down and they can’t digest their food as efficiently, making them lose most of their brilliant colors.


In the wild, discus fish change color to blend in with their surroundings and avoid predators. For example, if they are near some plants with darker colors, discus fish will turn dark to match the plants.

In your home aquarium, they may do the same thing if they feel threatened or are not comfortable.

I remember one time, I added a new fish to my tank and all of my discus fish bodies turned brown body. They were trying to blend in with the gravel so that the new fish wouldn’t see them!

After a few days, they slowly started to turn back to their original colors. However, this is normal behavior and nothing to be worried about. As long as they are eating and swimming around normally, they should be fine.


Discus fish are social creatures and live in groups. In the wild, they establish a hierarchy, with the most dominant fish being at the top.

The more dominant fish is usually brighter in color. However, as the submissive fish grows stronger, its hue improves while the previously dominant discus’ hues fade.

So don’t ever be worried if you notice this behavior. It’s perfectly normal and nothing to be concerned about! Just make sure that they are eating a nutritious diet and living in healthy water conditions.

Water Change

Generally, any changes in your discus fish’s environment can cause them to change color. This includes a water change.

Although these cuties like clear, sparkling water, they despise the procedure of obtaining it.

So, if you watch your fish change color during or after a water change, don’t panic! It’s perfectly normal.

Just give them a little time to adjust to the new water conditions and they should be back to their original colors in no time.

Also, make sure to carry out the process as smoothly and effectively as possible so that your buddies don’t get too stressed out.

Bright Lighting

I was trying once to make my discus fish look more beautiful by adding some bright tank lights.

However, I found out that this is not the case. In fact, too much light can actually cause your fish to fade.

To add natural and aesthetic beauty to your tank, it is best to use moderate lighting. This will help bring out the colors of your fish and make them look their best!


Although they are schooling fish, discus fish still need their personal space. Too much crowding in the tank can cause your fish to lose their color.

To provide your fish with enough space, you should have at least 50 gallons for a school of discus fish.

Dropsy Disease

Dropsy disease is a bacterial infection that causes your fish to turn black. This is a serious infection that can be fatal if not treated immediately.

For the least risk of infection, you should quarantine the infected discus fish and treat it with antibiotics.

Discus Fish Bloat

Bloating is an ailment in which your fish’s belly swells up.

This happens when the food is stuck in the digestive tract, preventing it from leaving via the anus and decaying instead within the Discus’ stomach, causing gas and fluid build-up

Consequently, they become stressed and darker in color.

Black Spot Disease

This disease is caused by flatworms that enter the skin of your discus via its scales and consume tissue and body fluid there.

These worms cause black spots to form on the fish, appearing as bumps from the outside. If there is a severe infestation, you will see many black dots all over the fish.

To treat the infected fish, remove the parasite from its skin with tweezers and apply an anti-parasitic medication.

White Ich

This infection, also known as White spot disease, is caused by a protozoan parasite that attaches itself to the fish’s body and skin to suck its blood.

Subsequently, the fish’s skin will develop a lot of white spots, which is why it is called white ich.

To treat this disease, you need to increase the water temperature and give your fish an anti-parasitic medication.

Black Plague

The black plague is a deadly viral illness that first struck Discus breeding farms in 1985. If this disease enters your aquarium, it has the potential to kill every last one of your fish!

As its name implies, the black plague turns the fish’s body black. Sadly, there is no cure for this disease and the only way to prevent it from spreading is to euthanize the infected fish.


Peppering occurs when you place the discus fish tank in a dark room or when the lighting in the tank is not bright enough.

Under these conditions, the fish will develop black spots on its body that look like flakes. However, this is not a concerning condition and your fish will return to normal once you adjust the lighting.


When discus fish are spawning, they will develop vibrant colors as they try to attract a mate.

After the spawning process is complete, the fish will usually return to their original colors. So don’t interfere with their spawning if you want to see them at their most beautiful!


Like any other shoaling fish, discus fish need the company of their own kind to feel secure.

If you only have one discus fish, it will become inactive and its colors will fade. To prevent this from happening, make sure to keep at least 3-4 discus fish together in the same tank.


Do Discus Fish Change Color As They Grow?

Discus fish change colors as they grow older. Juveniles will become more colorful as discus fry reach adulthood. However, the colors will eventually fade again as the fish age.

How Do I Enhance Discus Fish Color?

To increase your fish color, you need to provide them with good water conditions and a healthy diet. If you want to really make their colors pop, you can also try using special lighting fixtures that simulate the sun’s rays.

Why Do Discus Fish Change Color to Black?

There are various causes for your Discus to change its color to black, including:

  • Stress
  • Black Plague infection
  • Fish bloating
  • Dropsy
  • Black peppering
  • Camouflage

Last Words

Discus fish are some of the most beautiful creatures you can keep in your aquarium. However, they are also very delicate and require special care.

Make sure to research everything you need to know about them before getting started, and you’ll be sure to have a healthy and vibrant school of discus fish in no time!

I hope you enjoyed reading this article. If you have any questions or comments, please feel free to leave them below.

Happy fish keeping!