There are two main parts of the text that come to mind for you to focus on. The first is when Mr. Rochester explains to Jane about his first marriage and how he was manipulated into marrying Bertha Mason by his family to provide for him. In picking a match for his son, Mr. Rochester's father turns to an old acquaintance who made his wealth through colonialism:
"Mr. Mason, a West India planter and merchant, was his old acquaintance. He was certain his possessions were real and vast: he made inquiries. Mr. Mason, he found, had a son and daughter; and he learned from him that he could and would give the latter a fortune of thirty thousand pounds: that sufficed."
Thus Mr. Rochester found himself being sent to Jamaica to marry a wife that his father had courted from him. Of course, what we need to remember is that the wealth of such plantations was based on slave labour.
This is the case as well with Jane Eyre's uncle, whom we never actually meet, but plays a very important part in the novel by dying at an appropriate time and thus leaving Jane with an inheritance, turning her into an independent woman in her own right and thus making her the equal of Mr. Rochester. However, her uncle's money too would have been thanks to slave labour. Thus we can see that major elements of the plot of this excellent novel are tainted by the evils of colonialism.