How to use Dark Skin in Layout Editor?

Hello,

I've just updated MyGUI from SVN and noticed Layout Editor has a new skin (Dark Skin) which looks much better than the old Black Orange Skin, however, when creating UI it's still using Black Orange.
I've tried to mess with configuration but no luck. Any tips how can I make it use Dark Skin?

Thank you in advance.

create Button and change skin to Button_Dark
or
add skin Button_Dark in Widgets.xml