All the charts that show this are dealing in percentage of world GDP. This is really a meaningless statistic, and by itself doesn't show anything one way or the other about colonialism. Until the beginning of the industrial revolution, China and India were always 1 & 2 in GDP, because they were 1 & 2 in population. The biggest innovation of the Industrial Revolution was decoupling production from population.
Est. world GDP, 1750: $128 billion - India @ ~22% = $28 billion
Est. world GDP, 1950: $4 trillion - India @ ~ 4% = $163 billion