Many people are taken back by Colossians 2:16. The reason for this is because they have not come to uderstand the difference between the blessedness of the seventh day, which was created before sin, protected by Law of which Jesus is Lord of, and the shadows, which were instituted after creation as a result of sin to act as shadows.
The list of activities in Colossians 2:16 were institued as a result of sin and acted as shadows to help us understand how God was going to deal with sin through Jesus Christ.
Neh 10:33 for the showbread, and for the continual meal-offering, and for the continual burnt-offering, for the sabbaths, for the new moons, for the set feasts, and for the holy things, and for the sin-offerings to make atonement for Israel, and for all the work of the house of our God.
Ezek 45:17 And it shall be the prince's part to give the burnt-offerings, and the meal-offerings, and the drink-offerings, in the feasts, and on the new moons, and on the sabbaths, in all the appointed feasts of the house of Israel: he shall prepare the sin-offering, and the meal-offering, and the burnt-offering, and the peace-offerings, to make atonement for the house of Israel.
These shadows were instituted long after the seventh day was created and blessed by God.
So how do we know if the list of things mentioned in Colossians 2:16 were the shadows? By reading the verse 17. Verse 17 identifies these activities in Colossians 2:16 as the shadows that came as a result of sin.
Colossians 2:16-17 So let no one judge you in food or in drink, or regarding a festival or a new moon or sabbaths, which are a shadow of things to come, but the substance is of Christ.
To me, I see God making a distinction between the shadows that were instituted as a result of sin and the seventh day of creation, which was created as part of creation, protected by Law of which Jesus is Lord of. It's the only day in the NT that Jesus gave instruction on how to keep it holy.
The Sabbath also had its sacrifices, etc. and was a shadow as well. It was a sign of deliverance, being associated with deliverance from Egypt in Deuteronomy.
Per Hebrews 4 God's rest on the 7th day of Creation was a shadow of salvation by faith that we enter into.
Beyond that it was a sign with Israel, and part of the appointed times given to them.
And if you wonder how Hebrews could say that about something that happened before the fall, consider that Jesus was the Lamb of God slain "before the foundation of the world".
Of course it is debated whether the actual Sabbath institution came about at creation or later in commemoration of the creation event and the cessation of creation on the 7th day.
But we have additional biblical information that indicates the weekly sabbath is included in the verse.
Col 2:16 Therefore let no one pass judgment on you in questions of food and drink, or with regard to a festival or a new moon or a Sabbath.
Paul here groups together the festivals, new moons and sabbaths. By doing so he calls to mind several Old Testament texts that likewise group these days.
The weekly sabbath is included in the listing of appointed times in Leviticus 23.
This however, is not the only listing that groups the sabbath with these other times. Of particular importance is Numbers 28-29. It lists the sacrifices for the various appointed times. It includes the weekly sabbath along with the others.
The reason that it is of particular importance is because Numbers 28-29 forms the basis of several other references to these days in LIST form, similar to what we see in Col. 2:16.
Several of these are found in Chronicles. And they clearly refer back to Numbers 28-29 as they are talking about the sacrifices to be offered on the various days. Here is an example.
2Ch 31:3 He appointed also the king's portion of his substance for the burnt offerings, to wit, for the morning and evening burnt offerings, and the burnt offerings for the sabbaths, and for the new moons, and for the set feasts, as it is written in the law of the LORD.
This list form, Sabbaths, new moons, and set feasts, is very similar to what we see Paul using in Colossians 2:16. And we know that these included the weekly sabbath because they are summarizing Numbers 28-29.
That this listing includes the weekly sabbath is made even more clear in Ezekiel:
Eze 45:17 It shall be the prince's duty to furnish the burnt offerings, grain offerings, and drink offerings, at the feasts, the new moons, and the Sabbaths, all the appointed feasts of the house of Israel: he shall provide the sin offerings, grain offerings, burnt offerings, and peace offerings, to make atonement on behalf of the house of Israel.
The first time feasts is mentioned it is the chag, the three annual feasts. The summary "all the appointed feasts" are the moed, all the appointed times.
So we see that this listing of feasts, new moons and sabbaths includes all the appointed times. The appointed times included the weekly Sabbath in the two critical listings of them.
But we have further evidence in this case. The weekly sabbath is spelled out in the later explanation following the verse.
Eze 46:1 "Thus says the Lord GOD: The gate of the inner court that faces east shall be shut on the six working days, but on the Sabbath day it shall be opened, and on the day of the new moon it shall be opened.
Eze 46:2 The prince shall enter by the vestibule of the gate from outside, and shall take his stand by the post of the gate. The priests shall offer his burnt offering and his peace offerings, and he shall worship at the threshold of the gate. Then he shall go out, but the gate shall not be shut until evening.
Eze 46:3 The people of the land shall bow down at the entrance of that gate before the LORD on the Sabbaths and on the new moons.
Eze 46:4 The burnt offering that the prince offers to the LORD on the Sabbath day shall be six lambs without blemish and a ram without blemish.
Eze 46:5 And the grain offering with the ram shall be an ephah, and the grain offering with the lambs shall be as much as he is able, together with a hin of oil to each ephah.
So we have the summary statement of all the appointed times, Feasts, new moons, sabbaths, and then specific statements that indicate the weekly sabbath were included in that summary statement. This is just as we would expect because the sabbath was included in Lev. 23, and Numbers 28-29, as part of the appointed times.
Paul then is using a list that is a summary statement of the appointed times, including the weekly Sabbath.