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Blue: The Statement Matching this statement is on an empty box. The gems are in a box with a false Statement. There is at least one true statement on this box.

White: The gems are in a box with a true statement. The Gems are in a box with a false statement.

Black: The statement matching this statement is on an empty box. The gems are in a box with three statements. There are an equal number of true and false statement. 

C: Black Box

Blue: A statement with an odd number of words is always true. The gems are in the box with the most words.

White: False statements have less than six words. That's not true.

Black: This box has gems.

C: Black Box

Blue Box: A box that displays the word 'True' is false.

White Box: A box that displays the word 'Gems' is empty.

Black Box: The White box is true and does not contain gems.

Black Box is wrong!

I asked ChatGPT for help. Every time i ask him others he is 100% right. So this riddle is only doable with the solution or two keys. The solution should be Blue! (Need confirmation)

Blue Box: The Gems are not in this box. The Gems are not in the White box.

White Box: The Gems are not in this box. The Gems are in the Blue box.

Black Box: The Gems are not in this box. The Gems are in the Blue box.

C: Black Box