Hoat coolant isn't just one color although Hoat Coolant is mostly dyed yellow in color but Hoat coolant can also come in other colors such as green, orange, blue and even pink.
Hoat Coolant stands for Hybrid Organic, Acid Technology and the only way you'll know for sure you're using or have Hoat coolant is by the packaging.
Hoat coolant should not be mixed with other types of coolant because it can cause problems and if you know your vehicle is using Hoat coolant you should make sure your coolant container says Hoat coolant before adding any to your vehicles cooling system.