Colossians 1 (ESV)
20 and through him to reconcile to himself all things, whether on earth or in heaven, making peace by the blood of his cross.
This indicates God wants to save everyone. This verse immediately follows Paul talking about how Jesus created all things. That is the context. The context is not the creation of only the elect. The idea that Paul meandered from talking about how Jesus created all things to talking about how God wants to reconcile only a portion of them is implausible.
21 And you, who once were alienated and hostile in mind, doing evil deeds, 22 he has now reconciled in his body of flesh by his death, in order to present you holy and blameless and above reproach before him, 23 if indeed you continue in the faith, stable and steadfast, not shifting from the hope of the gospel that you heard, which has been proclaimed in all creation under heaven, and of which I, Paul, became a minister.
Here Paul seems to indicate the very real possibility that those who were reconciled would not be presented holy and blameless before God. But according to calvinism’s doctrine of limited atonement, the people who were predestined for eternal punishment were not reconciled to God by Jesus’s death. If the people Paul was addressing might not be presented holy and blameless before God, then two other calvinist doctrines must be false: unconditional election and irresistible grace.