https://en.wikipedia.org/wiki/Wikipedia:Reliable_sources/Perennial_sources
You can notice a bias towards the state media from pro-capitalist regimes from the above.
The suggestion was that OP could simply make an article and reference works that make a strong case for that claim.
It doesn’t appear to be difficult especially in relation to colonialism.
Now if Wikipedia rejected a well researched, fairly written and referenced article, this would be a different discussion.