Mohandas Gandhi reflects the problems of empire and colonialism in at least two important ways. One of the sets of problems that he reflects is moral while the other is more practical.
Morally speaking, colonialism and empire are difficult to do correctly. At least to our modern way of thinking, it is morally wrong for one group of people to dominate another, to rule them, and to refuse to give them the rights they deserve. Gandhi became politically active because the British were doing these things. For example, one of his first major efforts was a protest movement against British laws that prohibited organized political opposition to their rule. Colonialism forces governments to infringe on the rights of the people they rule. This sort of infringement is what led Gandhi to start to work against the British government.
Gandhi also shows a practical problem with imperialism. If one country is going to rule another country, it has to have a large group of officials who can run its government. This is particularly true of a huge country like British India was. (Remember that it included what is now Pakistan and Bangladesh in addition to India, which is huge in its own right.) In order to get these officials, the imperial power must often educate natives of the country like Gandhi. Gandhi, we should remember, studied law in England. When so many natives become educated, they will no longer feel (if they ever did) that they should be subordinate to the imperial power. They will also have the education and knowledge they need to resist. Gandhi embodies this problem in that he used his English education to fight against English rule.
This last point is connected to the idea of Gandhi’s background. His father was a high official in the British government of one part of India. We can speculate that Gandhi’s privileged background led him to prefer to protest against the British in the way that he did instead of advocating for something like a violent revolution.