However, anything released in 1928 and earlier is fair game. That includes gloves (movie poster, Willie title card etc. from 1928 has gloves), colours, etc.
Link to only known remaining 1928 poster in colour: https://movieposters.ha.com/itm/movie-posters/animation/mick...
So really, the only limit is that you can't use the different eye shape, etc., or his signature exclamation "hot dog!" which came later.
However, anything released in 1928 and earlier is fair game. That includes gloves (movie poster, Willie title card etc. from 1928 has gloves), colours, etc.
Link to only known remaining 1928 poster in colour: https://movieposters.ha.com/itm/movie-posters/animation/mick...
So really, the only limit is that you can't use the different eye shape, etc., or his signature exclamation "hot dog!" which came later.