This program was difficult for me to do.

1. I did not understand simple co-ordinate system -of the x, y axis.
2. Neither did I understand that in order to draw an actual pattern in the playpen window it was necessary to use the plot() function multiple times - for each pixel point to be displayed on screen. The origin generally does not need to change, the co-ordinates can be manipulated by adjusting the values passed to plot.
3. I still find it hard to understand nested loops.

This was my first attempt at this program:
// cover playpen with tiles
#include <iostream>
#include "playpen.h"

int main()
{
        fgw::playpen paper;
        int color(0);
        int draw(0);
        int const x(8);

        int count(0);
        int y(0);
        // loop to move up y axis
        while (count <= 8) {
                draw = x;
                while (draw >= 0) {
                        paper.scale(32);
                        paper.plot(-draw, y, color);
                        paper.display();
                        --draw;
                        ++color;
                }

                draw = x;
                while (draw >= 0) {
                        paper.scale(32);
                        paper.plot(draw, y, color);
                        paper.display();
                        --draw;
                        ++color;
                }
                ++y;
                ++count;
        }

   draw = 0;
   count = 0;
   y = 0;

        // loop to move down y axis
        while (count <= 8) {
                draw = x;
                while (draw >= 0) {
                        paper.scale(32);
                        paper.plot(-draw, y, color);
                        paper.display();
                        --draw;
                        ++color;
                }

                draw = x;
                while (draw >= 0) {
                        paper.scale(32);
                        paper.plot(draw, y, color);
                        paper.display();
                        --draw;
                        ++color;
                }
                --y;
                ++count;
        }
std::cout << "color is " << color << '\n';

        std::cin.get();
}

Although it does work to fill the playpen window with all the colors the program over writes some tiles and therefore fails to deliver a full solution. In the end, the program solution was provided by Francis Glassborow posting the solution on usenet.