Dear Russ:

The context of this passage is that Jews were making judgments upon the Christians because they did not follow the Jewish festivals feast prescribed in the Old Testament. St. Paul is telling us where free from all that. St. Paul is telling us that the ceremonial practices the Old Testament are but a shadow of something to come. That's something the, with Jesus Christ.

the Catholic study Bible explains verse 16:

food ... drink ... festival ... new moon ...sabbath: Jewish ceremonial practices that are often grouped together in the Bible (Isaiah 1:13–14; Hosea 2:11; Judges 8:6; 1 Maccabees 10:34). The first two concerning kosher dietary restrictions, and the last three referred to liturgical feast days celebrated yearly (festivals), monthly (new moons), and weekly (Sabbaths). These ritual practices of the Old Covenant were mere "shadows" of the greater "substance" to come with Christ and the sacraments of the New Covenant.

St. Paul again reminds us that we are called to a life beyond regulations of the Old Testament:

do not handle … taste …Touch: a sarcastic strike at the Jewish agitators and colossi, for whom physical contact with corpses, lepers, and unclean food was an act of ritual defilement (Leviticus 11; 13:45-46; numbers 19:11-22). Paul implies that since the purity codes of the Old Testament have now been set aside,Will it would be a worst act of defilement for Christians to readopt the very practices that Christ died to nullify (Mark 7:14-23; Ephesians 2:15). Jesus launched a similar critique on the Pharisees in Luke 11:37-44.

Bottomline: Christians should not readopt the purity codes, dietary restrictions, and liturgical feast days of the Old Testament. In fact to do so, St. Paul suggests, would be a defilement and an offense to Christ. Christ has done away with those Jewish ceremonies to make way for the new liturgy and practices of the New Covenant.

The Church, which has been given the keys of the kingdom, has the authority from Christ Himself to promulgate new regulations, practices, and liturgy. As such, Catholics are required to observe all that the Church requires of us — Sunday liturgy, Holy Days of Obligation, Solemnities and Obligatory Feasts, Friday penance (abstinence from meat), and required days of fasting.

I hope this helps to understand these passages.

God Bless,
Bro. Ignatius Mary