What is the Difference Between Coolant Colors?

[McRuby]

Coolant colors mainly have the following differences: 1. Coolants of different colors have the same functions, which are antifreeze and cooling. The color does not affect their performance. 2. The color is merely a distinguishing factor used by manufacturers and does not indicate any special functions. 3. The reason for the variety of coolant colors is primarily due to the different formulations used by various manufacturers. In terms of composition, ethylene glycol is generally green, propylene glycol is red with a hint of orange, and glycerol is blue. Additionally, to prevent confusion with other liquids and accidental ingestion, many manufacturers add different color formulations for distinction.

[MacBrielle]

I once mixed green and orange coolants when changing the antifreeze, which almost caused a major engine overheating incident. The colors of antifreeze vary significantly: green is typically the old-school inorganic acid salt type, cheaper but needs replacement every two years; orange is Organic Acid Technology (OAT), more durable and can last up to five years; pink or blue might be hybrid HOAT types, commonly found in high-end vehicles. The colors serve as manufacturers' markers to indicate different internal additive compositions—mixing them can trigger chemical reactions forming gels or sediments, clogging cooling passages and impairing performance. Now I strictly use the manual-specified color to avoid issues—safety first.

[DelJulia]

For those who frequently work in the garage, coolant color is crucial. Green corresponds to traditional IAT coolant, which offers weaker protection and is prone to rust; orange is OAT-type, providing long-lasting anti-corrosion; pink or blue represents HOAT hybrid type with strong compatibility. The color differences prevent accidental mixing, which could otherwise accelerate water pump or radiator corrosion or even cause leaks. Choosing the right color to match your vehicle type saves money and ensures smooth, durable engine cooling. During inspections, I always stick to the original factory color and avoid cheap off-brand alternatives.

[VonJulianna]

Antifreeze comes in a variety of colors like green, orange, pink, and blue, resembling a palette. The main differences lie in the additive components: the old-style green type has a short lifespan and requires frequent changes; the orange type uses new technology for durability and corrosion resistance; the pink type might be specialized for certain vehicle models. Mixing colors is hazardous—it can cause scaling, clog pipes, and lead to engine overheating. Since my car specifies orange, I stick to the same color and never add the wrong type.