What Color Should Transmission Fluid Be?

pouring red transmission fluid

What color should transmission fluid be? Well, typically, new transmission fluid is dyed a translucent red color. However, there is more to this red fluid than first meets the eye. Knowing what to look for in your transmission fluid can save you from potentially costly repairs and even less-than-honest service shops.

Learn all about transmission fluid so you can make educated decisions about your car’s needs.

Why is transmission fluid red?

Transmission fluid doesn’t start out red. It’s dyed that color to distinguish it from your car’s other fluids: oil (amber), coolant (typically green), brake fluid (typically gold), wiper fluid (typically blue), and so on.

Of course, when answering the question, “What color should transmission fluid be?” we have to be careful not to answer with a blanket “red.” You can use perfectly good yellow transmission fluid or green transmission fluid should you choose.

We even have some customers call us and ask us why they have clear transmission fluid. For the most part, this is because they’ve recently checked their transmission fluid levels and found it hard to see the fluid on their dipstick. A quick wipe of the stick with a cloth or rag will reveal a bright red color (and help you check for symptoms of low transmission fluid)

All said, though, the majority of transmission fluid is red. (Note: some brands of antifreeze fluids such as Dexcool® can also be red.)

How can I tell if my transmission fluid is OK?

As your transmission fluid is circulated over and over again, it will slowly begin to change color from its original bright red/pink to darker and browner colors. If your transmission fluid color is brown, don’t immediately start to worry. This transition is a natural part of the process and likely just indicates that it may soon be time for new fluid.  

It’s important to realize that there are other characteristics of your transmission fluid that might indicate a problem. For example, if coolant or antifreeze is leaking, the transmission fluid thickness might change. Coolant or antifreeze mixed with your transmission fluid can result in thinner, more viscous liquid. It may also cause foam or excess air bubbles.

Why does transmission fluid change colors?

Once people know the answer to the question, “What color should transmission fluid be?” they want to know why the color of transmission fluid changes. The answer to this question can be found by looking at the function of transmission fluid.

Transmission fluid circulates throughout your transmission, which controls how much power should be transferred to your wheels to reach the correct speed. The transmission heats up with use, and it’s the job of the transmission fluid to absorb that heat and lubricate the transmission’s moving parts. When the transmission fluid absorbs and expels the transmission’s heat, its chemical composition begins to change. 

As the fluid becomes less capable of transferring heat, it will turn dark red, then brown.

What is burnt transmission fluid?

Burnt transmission fluid occurs when the fluid is no longer taking away enough heat from the transmission. Burnt transmission fluid is black and is often accompanied by a burnt smell.

If you notice that your transmission fluid is black, check for small metal shavings in the transmission pan. These shavings can indicate an internal problem with your transmission that will need addressing quickly. Otherwise, your transmission will eventually fail, and you will be faced with either costly repairs or the need to purchase a new vehicle.  

How can I make sure I don’t have issues with my transmission fluid? 

The best way to make sure that your transmission and transmission fluid are in good shape is to have your car checked on a regular basis. After all, the Texas car inspection cost is much less than replacing your transmission.

At Colony One, we make sure that our customers and their cars are safe to go out on the road. That includes checking your transmission fluid.

If you’re not into getting under the hood and/or are too busy to check and replace your transmission fluid, call Colony One Service at 281-800-9209 or contact us online today. Ask us what’s included in our tune-ups and about our car repair warranty!


More Helpful Articles by Colony One: