Describes style information for a text track.
Colors are represented as strings “#RRGGBBAA” where XX are the two hexadecimal symbols that represent the 0-255 value for the specific channel/color. It follows CSS 8-digit hex color notation (See http://dev.w3.org/csswg/css-color/#hex-notation).
Background RGBA color, represented as "#RRGGBBAA". The alpha channel should be used for transparent backgrounds.
Custom application data.
RGBA color for the edge, represented as "#RRGGBBAA". This value will be ignored if edgeType is NONE.
If the font is not available in the receiver the fontGenericFamily will be used.
The font scaling factor for the text track (the default is 1.0).
Foreground RGBA color, represented as "#RRGGBBAA".
RGBA color for the window, represented as "#RRGGBBAA". This value will be ignored if windowType is NONE.
Rounded corner radius absolute value in pixels (px). This value will be ignored if windowType is not ROUNDED_CORNERS.
The window concept is defined in CEA-608 and CEA-708, See http://goo.gl/M3ea0X. In WebVTT is called a region.