Is there any way to change the visual style of the interface buttons in OS X? For instance, in Tiger, the blue/grey "OK" or "Cancel" buttons in a window had a rounder radius. In Mavericks, they're more rectangular. Are the button images stored in a resources folder somewhere in the Library? Is there a safe way to change them?





Thanks!
There isn't a general one place to change these and when you do, it's typically with software additions that make the system less stable.

You would have better luck changing them on a per-application basis since that is less disruptive of injecting custom code across all applications. Even then, you'll find that some applications hard code their buttons and they only look like the system ones.