This is just false, there is little evidence to suggest anything of the kind. China wants to secure its imperial borders (Tibet, Xinjiang) as a show of national pride, and it wants to ensure the security of its people by making sure the islands in front of the mainland can't be used to stage an attack and the SCS cannot be blockaded by the US. American senators and generals proudly proclaim they have the power to starve the Chinese with a blockade in the SCS or block access to the Pacific - it is only natural for China to not want to be in that situation.
None of the actions China resembles European colonialism.
There is actually some truth to that. China has very poor access to the ocean, so they are pretty easy to blockade. But this is true even if they can successfully colonize the South China Sea. There are just way too many countries around that part of the world who aren’t in China’s corner, who are mostly afraid of China after being invaded by it for thousands of years.
None of the actions China resembles European colonialism.