SetBackgroundColor
void SetBackgroundColor(rgb_color);
return SetBackgroundColor((rgb_color){ r, g, b, a });
CharacterStyleDataRef data = fStyleData->SetBackgroundColor(which);
CharacterStyleDataRef data = fStyleData->SetBackgroundColor(color);
bool SetBackgroundColor(
bool SetBackgroundColor(color_which which);
bool SetBackgroundColor(rgb_color color);
CharacterStyleDataRef SetBackgroundColor(color_which which);
CharacterStyleDataRef SetBackgroundColor(rgb_color color);