Because the player is an iframe, you can’t customize the CSS in your HTML.
Background/text color seems straightforward and something we will consider adding support for. Can you share more about your use case for using web-fonts? Is the primary purpose to match your brand’s font or are there other reasons?
is there any update related to this? It would be awesome to be able to change or remove the black background of the captions… also its position, because the default one feels kind of too close to the bottom.