My Bold 9900 runs on AT&T so the default or stock is a translucent white and blue ball, AT&T Logo. No matter the NO release of Theme Studio 7 there are devote, consistent, brightfull and gorgeous themes for the Bold 9900. Some themes producers names; drkapprentice Designs, Julnt Designs, Walker Themes, bbthemelab, Raypho, BBThemes and Elecite.
It varies. I love themes so I go through cycles where I change them whenever one I like catches my eye. But I also like to go long periods with the regular BB 7 theme. It's very clean and I love the standard icons.
I'm currently using the iOS 7 theme that was featured in this weeks Theme Round up. I highly recommend it!