Do skins on an iPhone Simple UI make it less Simple?

I mentioned Minu Timer before as an app I use as a iPhone based timer that removes the clutter and just gets the job done. Upon launch, twist the face one way to start a stop watch, the other way to a time as a count-down timer.

A recent update to the Minu Timer offers the ability to change skins. The feature requires an upgrade to the 99 cent ‘Pro’ version though.

Unlike many ‘Pro’ theme updates in other apps, you get access to all 6 new themes with the one buck fee.

The theme changes in Minu Timer is nothing more than colors and accents. Making the experience more personalized to the way a person feels comfortable with. No functionality, features or addition of buttons, just enhancements to the accents. This doesn’t change the User Interface, but should we consider it a change to User Experience?