Click the checkbox next to each dropdown menu to allow or deny video the ability to override each setting.Click the dropdown menu next to Text Size.Click the dropdown menu next to Text Color.Click the dropdown menu next to Background Opacity.Click the dropdown menu next to Background Color.Enter a name for the style next to Style Name.How to create custom captionsĬlick the + button below the three style presets. The window above the choices will preview each one so you can decide which works best for you. Click Captions in the menu on the left.Click the Apple menu button on the top left of your screen.How to enable closed captions and SDH by default.If the default reverse text is too hard to read, you can switch it up to different presets or create your own. And you don't just have to stick with one style. Just like enabling closed captions on your TV, you can do the same in Accessibility on your Mac, and they'll be there for you when available.