People worked under low working conditions and there was a rise of child labor due to the IR. People with high skills tend to receive more wage and live in better houses than those who have lower skills.
There are other effects of IR as well: Increase in food supply, larger population, more need for raw materials, want for bigger markets to sell goods and make more money.
So, how did it lead to colonization and imperialism?
IR gave the motive and the ability to colonize Asia and Africa for trade routes as well as raw materials. Countries demanded more raw materials and bigger markets. So they start colonizing other countries to take their resources and sell good in their market.