OBS Studio supports custom user themes to customize how OBS looks and feels. This video looks at 9 themes for OBS that you may want to consider using and how they affect the UI.
- Ocean Blue – https://obsproject.com/forum/resources/ocean-blue.1327/
- Flat Dark Theme – https://obsproject.com/forum/resources/flat-dark-theme.616/
- High-DPI Eye Friendly Dark Theme – https://obsproject.com/forum/resources/high-dpi-eye-friendly-dark-theme.951/
- Light Theme – https://obsproject.com/forum/resources/light-theme.1247/
- CGC OBS – https://obsproject.com/forum/resources/cgc-obs.1184/
- StreamLabs Theme – https://obsproject.com/forum/resources/streamlabs-theme.887/
- Twitchy – https://obsproject.com/forum/resources/twitchy.813/
- YouTubey – https://obsproject.com/forum/resources/youtubey-wip.817/
- Mixery – https://obsproject.com/forum/resources/youtubey-wip.817/
You can learn how to install OBS themes here.