The cost of developing colonies to mainland standards

What if an empire tried to develop its colonies to the same standard as the mainland from the seventeenth century onward?

The colonies could be far more developed by the 1940s, but the policy would require centuries of sustained building, investment, and credit.

Bringing colonies to mainland standards would require sustained construction, investment, and credit from the seventeenth century onward. If that effort succeeded, the empire could be more industrially advanced than historical powers were in the 1940s. No particular sectors, regions, or measurable development level are specified. The conclusion depends on maintaining an exceptional financial commitment for centuries.