Coolant Colors: Why They Matter and How to Choose Right

You pop the hood. The coolant reservoir is low. You drive to the nearest auto parts store, grab a bottle of bright green antifreeze, and pour it in. It is all the same, right? It is just colored water.

That assumption could cost you an engine.

The days of "one coolant fits all" are long gone. Modern engines are built with aluminum heads, plastic radiator tanks, and sensitive water pump seals. They require specific chemical cocktails to prevent corrosion, cavitation, and electrolysis. Using the wrong coolant—or mixing two different types—can turn your cooling system into a gel-filled nightmare.

Here is what you need to know about coolant colors, why they matter, and how to avoid destroying your radiator.