When you mix the wrong color of antifreeze or coolant in your car then the additives in those coolants will not work properly.
Then your engine can suffer damage from overheating and corrosion.
That corrosion can happen to the radiator, engine, water pump, head gasket etc and then lead to damage on the engine.
Always make sure you add the correct coolant to the car because it does matter what color of coolant you use in your coolant system on your vehicle.
The wrong coolant can cause a costly repair to be needed to your car.