You can change the font, size, shadow, and background color of subtitles and closed captions.
Go to your Netflix Account page.
From the Profile & Parental Controls section, select a profile.
Select Change for Subtitle appearance.
Choose your subtitle appearance settings.
Open the Netflix app on your device to start watching with your new subtitle appearance.
Begin playing a TV show or movie.
From the player controls at the bottom of the screen, select Settings to adjust subtitle Size and Style.
Choose your Size and Style preferences.
Resume playing the title.