Earlier, Paul said that we are to teach and proclaim the gospel in a state of wisdom (Colossians 1:27-28). He emphasizes properly knowing the mystery of God, which is the Person of Jesus Christ (Colossians 2:2-3). Philosophy necessarily involves the acquisition of wisdom.
There exists good philosophy and bad philosophy. The former is rooted in sound theology. The later is rooted in human speculation. Philosophy is not to be developed apart from or against the content of divine revelation. It is bad kinds of philosophy that we must condemn.
Paul exhorted the church at Colossae not to be deceived by various customs and practices rooted in Jewish and pagan mysticism (Colossians 2:16-23). In so doing, he was very much setting forth a philosophical proposition. Everybody engages in philosophy at some level.