it is normal after few hours after the engine off the cooler pink (antifreeze) down to the low gauge ? when I turn on engine the cooler up to the middle ....
You have two marks on the resevior. The highest mark is the maximum mark to avoid "boil-over" when hot, and the lower mark is the minimum or LOW mark. I would suggest filling to the upper mark when your engine is cold.
Go to the dealer, and then you don't need to worry about buying the wrong type. You'll have it forever unless you are leaking coolant. It's a mix of antifreeze and water.