Scroll View with transparent background (Objective-c Mac OS X)

I have a Scroll View in my Mac app with a white background but I want the background to be completely transparent开发者_如何学Go. I changed the opacity of the background to 0 but that doesn't seem to help, so I added an image of my settings and i was hoping you maybe were able to see the problem

Thank you in advance!

is this for a 10.7 App? If so it should just work out of the box. If you are doing 10.6 or earlier you might have to implement your own custom scrollbar or use a toolkit like Chamelion,etc to get the effect you are looking for. Only 10.7 has overlay scrollbars by default, prior to this the OS scrollbars subtracted area from the content view to dedicate to scrollbars.

On iOS, you just set the background to the clearColor. It seems logical the same would apply to the Mac.