It seems people always use these words to war up. They have same pronunciations, are they antonyms? I can't find them in any dictionary.
支人 is the abbreviation of 支那人. 支那 was originally India's ancient name for China, and was later used by Japan. It has now become a derogatory term, somewhat similar to calling a Japanese Jap. "支那人" is often used on the Internet by Chinese languges users who oppose the Chinese government, and it is used to refer to Chinese people who are too patriotic, similar to 小粉紅. For example, in Taiwan, the term of Mainland China is often called 支語. But in some times, this is a severely discriminatory term.
殖 in 殖人 mean 殖民(colonization), and 殖人 are those who support colonialism and colonialist countries. It is a derogatory term to describe Chinese people who tend to be liberal and close to Western culture. For the more patriotic Chinese, the colonizers do not identify with their own country, but are spiritually colonized by Western countries, similar to "Boba liberal".
支人 and 殖人 represent opposing positions in politics, which is why you mentioned that he was used to war up. To put it simply, for the 殖人, the 支人 blindly followed the Chinese government; for the 支人, the 殖人 blindly followed Western values.
殖人 is literally a colonizee, someone who has been colonized. It is used to refer to Chinese people who are more liberal or more Western-facing/supporting.
支人 is a derogatory term to refer to Chinese people. It is usually used by overseas Chinese to talk about certain overly-patriotic Mainlanders. See: Wiktionary | 支那人