In the debut, Lee chose grey for the Hulk because he wanted a color that did not suggest any particular ethnic group. Colorist Stan Goldberg, however, had problems with the grey coloring, resulting in different shades of grey, and even green, in the issue. After seeing the first published issue, Lee chose to change the skin color to green. Green was used in retellings of the origin, with even reprints of the original story being recolored for the next two decades, until "The Incredible Hulk" vol. 2, #302 (December 1984) reintroduced the grey Hulk in flashbacks set close to the origin story. An exception is the early trade paperback, "Origins of Marvel Comics", from 1974, which explains the difficulties in keeping the grey color consistent in a Stan Lee written prologue, and reprints the origin story keeping the grey coloration. Since December 1984, reprints of the first issue have displayed the original grey coloring, with the fictional canon specifying that the Hulk's skin had initially been grey.