How to change the action of NSColorWell?

I can use NSColorWell as button to change the color of selected text. Since NSColorWell is object of an NSControl it has target and action. I guess, the action is implementing the code to change the color of the selected text in NSTextView. Where can I find this code for NSColorWell action? I would like to change it in away that I can use NSColorWell to change the background of the selected text, and ultimately to have in ToolBar two NSColorWell buttons: one to change text's foreground color and second one for text's background color.

Solution

NSColorWell is just a rectangular control to change a color.

You can either create an IBAction and connect it to the action of the color well in the Connections Inspector (⌥⌘6) of Interface Builder
```
@IBAction func changeColor(_ sender : NSColorWell)
{
   let color = sender.color
   // do something with the color
}
```
Or bind the value in Bindings Inspector (⌥⌘7) of Interface Builder to a dynamic property, this example will set the color well to a default value of green.
```
dynamic var color : NSColor = .green {
   didSet {
     // do something with the color
   }
}
```