What clues does Steinbeck give us that mark Curley's wife as significant?

Context: Curley's wife is the only woman on the ranch, she is alone in a mans world. Immediately this marks her out to us, as contextually she would have no power or status(lack of womens rights at the time), and is living in a ranch which is traditionally a male dominated environment. Her reaction to her position, considering the time period, means we must regard her as significant in some way or another. 

Behaviour/ Appearance: Consistent mention of the colour red when regarding her appearance, this has connotations of danger, and is almost foreshadowing her tragic ending (alongside the repeated emphasis on 'the movies.') Eye catching, bright colour that does not go along with the meek appearance women were expected to display at the time. Referred to as a 'tramp' and 'tart' by the other characters on the ranch, that makes us question her behaviour, and ultimately is Steinbecks way of showing us she will be significant to the plot.