"Johns' Color Numeral Series, and especially this print, Figure 7, are examples of his greatness as a printmaker. To create this print, colors were applied to the palette and rolled onto the stone in one sweep. Johns devised a systematic formulation of the color progressions: the 0 begins with the three primaries: red, yellow, and blue; the 9 ends the series with the three secondaries: orange, green, and purple -- the new colors are always introduced at the top of each succeeding image, so that the series emphasizes the flow and continuity fo the color fields. The colors of Figure 7 are purple, red and orange. Johns pictures Mona Lisa because he has been a lifelong fan of Marcel Duchamp's work." (Field, 1970; pp. 104-13).