When you make a new GUI skin it nicely comes in with all sorts of preset colours etc.
If you then change one of those elements to a custom image how do you change it back to the default?
For example I accidently changed the horizontal slider element to an image when I meant to change the horizontal scroll bar. Now when I select the background slot it only gives me a list of images in my asset folder how do I change it to just “horizontalslider” which is the default in a new skin.
create a new GUI skin then import what you want over to the other one or if you still have it open apple-z
Undo-ing works when you have just done it - but sadly it was too late for that.
How do you import want you want from a new skin?
I can import an entire skin but not an individual element of that skin.
download the builtin skin
http://unity3d.com/support/resources//files/BuiltinSkinSource.zip
or download the other ones
http://unity3d.com/support/resources/files/ExtraSkins.unitypackage
then just import the images into your one.