In the 1600's Sweden became one of the most important powers in Europe through its huge military victories and it even managed to get a colony in North America. I know that the colony of Nya Sverige of quite short-lived and after The Great Northern War Sweden started to decline, but what was the Swedish opinion of slavery during this time period? If Nya Sverige had managed to be a profitable colony and grown, would Sweden embrace slavery practices like how the other European colonizers did?
What was the Swedish perspective on slavery in colonial times?
Very similar to the other European colonizing powers.
New Sweden was a success and a failure. They were the only colonists to really maintain a mostly peaceful relation with the local inhabitants and focused largely on trade, which allowed them to stabilize as a colony. A series of conflict with the Dutch in the 1640s and 1650s left the two neighboring colonies fighting for what would become mainly Delaware, with both gaining the upper hand at times. The trade for food with local tribes working large established fields and lack of reinforcements coupled with constant bickering with the Dutch (and for a short time the English) never allowed much in the way of plantations to develop, which was certainly one of their motivators for colonization - they had hoped to break in on the tobacco trade flourishing at that time. In this regard they failed to establish the colony they had intended to form and profit from.
The first enslaved man known to be in New Sweden was there from the beginning. Antonius, also known as Black Anthony, came to the colony aboard a Swedish vessel in 1639 (the colony had been formed the year before). Much like the original crew unloaded in Jamestown twenty years earlier, he was able to gain his freedom and even worked for the Governor of the colony, changing his name post freedom to Antoni Swart. This was previous to English law permitting race based slavery even in the colonies (but not by much, and with an arguable exception of Barbados starting in 1636), so it isn't terribly surprising to see the Swedes take the same approach of working for freedom.
A much more clear example emerges in 1784 in the wake of the American Revolution. A small French owned Caribbean island, Saint Barthélemy (commonly called St Bart's today), was traded to the Swedes. Since slavery existed in practice on the island, they were faced with the choice of how to proceed. They chose to permit slavery to tend the lucrative plantations already established that they now possesed, and that continued until 1840. So they literally did embrace it just as other nations had, although to a far smaller scale.
In addition to this, the Swedes actively participated in the Atlantic Slave Trade. While a very minor player in the overall, some estimates put Swedish vessels as the means of transportation for some 10,000-15,000 enslaved Africans. They certainly had no qualms with it and but for lack of opportunity became a lesser player in the overall. I can't say what could have happened if it all happened differently, but had they established a colony in, say, Carolina in the 1650s, there is no doubt in my mind it would be a different story regarding their level of participation in using forced labor in that timeframe.