An interesting feature request from a user of my power tabs KPCTabsControl on OSX: make them vibrant in Yosemite. The effect is subtle, but I managed to implement it. It requires some additional work though before release, to make sure the core feature of KPCTabsControl continues to work on older versions. 

On Yosemite, make sure to use a NSVisualEffectView as container view, and that this view is layer-backed. The demo app will have everything for you to check.