It wasn't. Those resources were taken away from the colony into Europe to be processed into materials which they sold back to the colonies (meaning taking the money from the purchase and pocketing it into the colonial overlords hands)

Sound familiar? Yeah it was what the British did to America (grow cotton, take it to Britain, turn it into textiles, sell it back to the colonies). It was an exploitative system that: Prevented the colony from industrializing (since instead of just taking that raw material locally to a factory to be processed they were just shipped away), Made the local economy a bit poorer (since instead of the locals then buying those processed goods from local factories, the money was going overseas and entering into their market instead, making the local areas poorer), and most importantly stifled any growth of a modern state by depriving it of technically competent people which emerge from industrialization (capitalists, engineers, etc.)

To find out more, google British deindustrialization of Bengal/India. The British practices in Bengal helped turn a proto industrial economic powerhouse (Bengal was 15% of world gdp and had a massive textile industry that exported worldwide) into a cash crop hell hole (they forced locals to grow cash crops like opium that could not be eaten, causing famines as well, where previously the locals grew food which meant fewer and less severe famines)