Kodi builds can drastically change the look and feel of your media center, but they’re usually bundled with lots of copyright-infringing addons (and there’s a good chance some of these will be broken or outdated anyway).
We’d advise staying away from Kodi builds for one main reason: they can cause problems that are hard to diagnose since you don’t know every addon that’s installed. If you’d like to tweak Kodi’s appearance, you might want to try a Kodi skin instead — these are more lightweight and don’t include any of the additional bloat that a fully-fledged build does.