Firstly, Österbotten and other Finnish regions did not became Swedish colonies when they were incorporated in the Swedish Kingdom in the Middle ages, in the same way Skåne did not become a Swedish colony when it became a Swedish province in the 17th century. Administratively, these regions were Swedish provinces (landskap) and not Swedish colonies, fully incorporated in the Kingdom of Sweden. Finland and Sweden was one country.
Secondly, since you claimed there is racism today towards Finns in Sweden, I corrected you by the fact that you didn’t separate between racism and xenophobia. Finns are not attacked on the streets in Stockholm based on their “Finnish race”, in the way African Immigrants are, simply because Finns and Swedes are indistinguishable. Nor have any relatives or friends in Sweden been attacked or threatened by ethnic Swedes simply because they speak Finnish. Never, ever! I, my family, friends, acquaintances and other Swedish speakers are however attacked and threatened on a daily basis, simply because we speak our own language in the Capital of our country. Finns in Helsinki are by far more hostile against Finno-Swedes (very), than Swedes in Stockholm are against Finns (not at all). In this respect xenophobia is much more prevalent Finland than in Sweden, at least in respect to Finns in Sweden, and Finno-Swedes in Finland. This in an indisputable fact.
Finland was never a Swedish colony, rather it was a fully integrated part of Sweden during the Sweden rule. Geographically, North-Western Finland is part of the Scandinavian peninsula, however culturally Finland is clearly not (a very different language). Many traditions (the summer graduation song called Suvivirsi, Thursday pea soup with pancakes etc), religion (Lutheran) and politics (the Nordic welfare state) are the same or very similar. Since there is no such thing as a Finnish race, there is no racism towards Finns in Sweden, and xenophobia towards Finns have nowadays been replaced with other ethnic minorities, such as Somalis. However, racism and xenophobia is profound in Finland. Many Swedish speaking Finns are attacked by the Finnish majority population on a daily basis (warning, don’t speak Swedish on the Helsinki subway) and told to go “home to Sweden”, although Swedish speaking Finns have lived in Sweden since the founding of Finland in the Middle Ages.