So i allway say this bottle of pink fluid under my hood but never knew wat it was for. i just assumed it was like soap or something for the winsheild washer. but when i found my real winsheild washer tank i started to wonder wat its was for and eventuall i found that it was my reserve coolant tank. so now im wondering why its pink instead of green? does this mean it has to be changed or do chevy dealerships just use some sort of pink coolant???