At first in "Donkey Kong", Mario was a carpenter. In "Mario Bros.", Mario and Luigi were designed as Italian plumbers by Miyamoto, on the suggestion of a partner. Software limits at the time—almost the same as those that gave Mario his special look in "Donkey Kong"—meant the first appearance of Luigi was limited to a simple palette swap of Mario designed to be the second player. The characters were in every way the same, other than their colors. The green color for Luigi would last as one of his physical characteristics in future releases.