Samsung UN40EH6030 E-Manual page 21

Background Co,or: You can change the background color of the caption.
Options include Default, White, Black, Red, Green, Blue, Yellow, Magenta and
Cyan. The default is Black.
Font Opacity: This adjusts the opacity of text. Options include Default,
Transparent, Translucent, Solid and Flashing.
Background Opacity: This adjusts the opacity of the caption background,
Options include Default, Transparent, Translucent, Solid and Flashing,
IRetu to IDefau_t: This option sets Size, Font Style, Font Color, Background
Color, Font Opacity, and Background Opacity to their defaults.