I know this is highly outdated but here is a link to some skins that should work on any Sense 3.0 devices.
For that certain clock mentioned in the OP. Try Blue Glass. It's only a skin its removeable.
I wouldn't recommend flashing anything that requires using recovery. It mite change the framework. But Skins are basically apps. Just install it like an app and remove like an app if you don't like it.
Wait....I sent this with Tapatalk?