You can now alter subtitle appearance on the Viki web player.
Simply click on the Settings gear icon at the bottom right of the video player and select Subtitle Appearance.
Font: Select the font style which you prefer your subtitles in
Size: Select how big/small subtitles should appear
Text color: Select the color the subtitles appear in
Background color: Select whether there's a background behind subtitles and what color it shouldappear in. Videos with hard subs will always have a background to enable easy reading.