iOS 7 modal view makes buttons grey (disabled)

I'm upgrading an app to iOS 7 and am running into a problem where all buttons turn to grey after I display a modal view. They're still clickable though. It only happens with modal views and not popovers.

As @CarmeloS points out the tint color is most likely your problem. Look at UIAppearance and or another view/viewcontroller higher up in the view heirachy as I believe this is now an inherited trait. So you may have set it it elsewhere.