You dismiss Col 2 Scripture as being less important than Scripture in the gospels. Or, you accuse Col 2 Scripture of contradicting gospel Scripture.
Either way, all Judaizing sabbath-commanders today preach OT law of Moses over NT doctrine of Christ, rather than conforming the old to the new.
The NT apostolic doctrine of Christ is that holydays and sabbaths can no longer be transgressed nor profaned, because they are no longer commanded by law of Christ for His NT churches to faithfully keep.
All of the old law were good to obey, and are still good to adopt, but no longer commanded as law to keep, on pains of trasngression.
Col 2:16
Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days: Which are a shadow of things to come; but the body is of Christ.
Whether it's foods, drinks, or days; all Christians are free by personal liberty to eat, drink, and keep as we desire. But none of those things that were commanded in the old law of Moses, are commanded in the new law of Christ.
Those who command any of these old things for all new Christians to obey, are making themselves false lawgivers and judges, instead of the only true Head of the body, Jesus Christ.
Jas 4:11
Speak not evil one of another, brethren. He that speaketh evil of his brother, and judgeth his brother, speaketh evil of the law, and judgeth the law: but if thou judge the law, thou art not a doer of the law, but a judge. There is one lawgiver, who is able to save and to destroy: who art thou that judgest another?
Col 2:20
Wherefore if ye be dead with Christ from the rudiments of the world, why, as though living in the world, are ye subject to ordinances, (Touch not; taste not; handle not; Which all are to perish with the using) after the commandments and doctrines of men?
What's only worse, is the open insult, that none of the congregations of those lawgiving sabbath commanders, even keep their sabbaths themselves.
I mean, if you're going to command a special law to make yourselves special, you ought at least keep it special, rather than breaking it by allowance with corban dues....All pseudo-sabbath congregations are manifest frauds, that can't even keep it special when commanding something special.
What? You want all churches of God to be like you? To preach a lying commandment, with built-in exceptions and allowances and donated sabbath paydays? Forget it pal.
2Jo 1:9
If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him God speed: For he that biddeth him God speed is partaker of his evil deeds.