render_background (Gruff::Base)

    # File lib/gruff/base.rb, line 875
        def render_background
          case @theme_options[:background_colors]
          when Array
            @base_image = render_gradiated_background(*@theme_options[:background_colors])
          when String
            @base_image = render_solid_background(@theme_options[:background_colors])
          else
            @base_image = render_image_background(*@theme_options[:background_image])
          end
        end