Polar
Polar makes coolants and car wash chemicals. Autotools stocks Polar coolants rated to -37 °C for several specifications, microemulsions, engine wash, tar remover and brake fluid.
Coolants come in red, green, blue LLC and yellow VCS-2, plus Premium Long-Life G12evo and VC. For washing there is a microemulsion soaking agent in 10 l cans and spray bottles, engine wash, tar remover and a pressure washer shampoo.
Colour does not decide which coolant to use; the type your carmaker requires, such as G12evo, does. If you are unsure what is in the system, flush it before refilling.