Swift 3.0为MapView设置注释引脚颜色

I am having trouble setting a pin color for my map annotation. I have a function in my MapView viewcontroller that pulls from an array from another view controller and depending on the case of the type, I want different pin colors for the map view. I am not sure how I can add the pin color information to the annotation within this switch statement. My understanding of annotations is rather weak so any explanations, rather than the solution itself, are greatly appreciated.I am having trouble setting a pin color for my