element - Name of an HTML element for which to return font information (e.g. p, h1); if omitted, returns information about the frame's default font (string)
Returns:
shadowR - Red component of the shadow color (0.0 - 1.0) (number)
shadowG - Green component of the shadow color (0.0 - 1.0) (number)
shadowB - Blue component of the shadow color (0.0 - 1.0) (number)
shadowAlpha - Alpha (opacity) of the text's shadow (0.0 = fully transparent, 1.0 = fully opaque) (number)
