def bg=(color)
      color = Color.new(color)
      @ctermbg, @guibg = color.to_cterm, color.to_gui
      self
    end
def bg=(color)
      color = Color.new(color)
      @ctermbg, @guibg = color.to_cterm, color.to_gui
      self
    end
Set both ctermbg and guibg simultaneously

 @param [String] color
   the color to use

 @return [Vic::Highlight]
   the updated highlight

 @api public