I am just now getting into playing with the Skins (up to this point I have just been using the standard Gray) any way I have noticed a few issues.
I have a top menu bar in my application. If I change the skin to either 'Black' or 'Olive' the text in that menu bar is now bold. The issue is that you can no longer see the entire text of the menu item as the bar does not resize in response to the change to bold text.
The second item is when diplaying reference objects. The top right menu items available for that reference object has a 'Convert query results to a printer-friendly format' button. If I change the skin to any of the following 'Olive', 'Purple', 'Black' or 'Gray' this button disappears from the reference object. Also, if I set a visual perspective to one of these four colors as default the button will not show up.