You can specify closed-caption formatting.
// Set CC style.
var tf = new AdobePSDK.TextFormat(
AdobePSDK.TextFormat.FONT_DEFAULT,
AdobePSDK.TextFormat.COLOR_DEFAULT,
AdobePSDK.TextFormat.COLOR_DEFAULT,
AdobePSDK.TextFormat.FONT_EDGE_DEFAULT,
AdobePSDK.TextFormat.COLOR_DEFAULT,
AdobePSDK.TextFormat.COLOR_DEFAULT,
AdobePSDK.TextFormat.SIZE_DEFAULT,
AdobePSDK.TextFormat.DEFAULT_OPACITY,
AdobePSDK.TextFormat.DEFAULT_OPACITY,
AdobePSDK.TextFormat.DEFAULT_OPACITY;
mediaPlayer.CCStyle(tf);
Browser TVSDK does not support font edge, fill color, or fill opacity.