Thinking ahead about avoiding confusion: Perhaps you might rename the 'ObjectBar theme' to 'ObjectBar construct' to better communicate that it is not simply a thematic variation, like a skin, but actually a new design.
'ObjectBar skins' will only be able to change the appearance of existing constructs; but constructs, as the name implies, can take any shape or form.
Please give 'construct' some consideration, as I think it is a clearer term than 'theme.'