Understandable, but technically wrong in Law, unless you have singled out that player and his jewellery and asked him to remove it. A general "no jewellery please lads" chat before the game is not the same.
And it would not be UB, rather Dissent by Word or Action.
That's the confusion, and you need to be specific which situation you are describing. I would also be careful about "as far as I'm concerned" because it should be as far as the Law is concerned. It is not down to your interpretation in this instance.